Conversion from string DEF to type Date is not valid

When I make the respective query with the Initial and Final dates, if you return the result of the query, however, it shows me the following error message:

"Conversion from string DEF to type Date is not valid.".

I think that you are not making the correct conversions of what you receive in the variable dates

start = startdate.Text  //Fecha Inicial
end1 = enddate.Text     //Fecha Final

The result of the query shows it, but without taking into account these color configurations

Grid1.Rows(x).Cells(y).BackColor = Drawing.Color.Yellow
                            Grid1.Rows(x).Cells(y + 1).BackColor = Drawing.Color.Yellow
                            Grid1.Rows(x).Cells(y + 2).BackColor = Drawing.Color.Yellow

That is, it is not entering into these conditions; painting in yellow indicates that when an employee is given a LOW, he must show the record or the column with his employee's data in YELLOW color.

If (Grid1.Rows(x).Cells(y).Text.Substring(0, 3) = "BJA") Then
                                Grid1.Rows(x).Cells(y).BackColor = Drawing.Color.Yellow
                                Grid1.Rows(x).Cells(y + 1).BackColor = Drawing.Color.Yellow
                                Grid1.Rows(x).Cells(y + 2).BackColor = Drawing.Color.Yellow

Full Frontend of the application: ASP-NET Form

Part of the form

Fecha de Inicio <asp:TextBox ID="startdate" runat="server"></asp:TextBox><br /> <cc1:CalendarExtender ID="Calendar1" runat="server" TargetControlID="startdate"> </cc1:CalendarExtender> Fecha final <asp:TextBox ID="enddate" runat="server"></asp:TextBox> <cc1:CalendarExtender ID="Calendar2" runat="server" TargetControlID="enddate"> </cc1:CalendarExtender>

Backend of the application

Imports System.Data
Imports System.Data.SqlClient
Partial Class _Default
    Inherits System.Web.UI.Page

    Dim a As Buayacorp.WebControls.DgToExcel
    Dim dt As DataTable
    Dim RowsCount As Integer = 10
    Dim i As Integer
    Dim start As Date
    Dim end1 As Date
    Dim dr As DataRow
    Dim dataa As SqlDataAdapter
    Dim datas As New DataSet
    Dim reader As SqlDataReader
    Dim fbaja As SqlDataReader
    Dim DataSet As DataSet
    Dim connString As New String("Data Source=000.000.00.00;User ID=ko;Password=12345678;initial catalog=bdd;")
    Dim conn As New SqlConnection(connString)
    Dim conn2 As New SqlConnection(connString)
    Dim cmd As SqlCommand
    Dim groupin As String
    Dim aux As String
    Dim aux2 As String
    Dim aux3 As String
    Dim sql As String
    Dim flag As Integer = 0
    Dim flag2 As Integer = 0
    Public cont As Integer
    Public group(24) As String

    Private Function GetMyTable(ByVal TableName As String) As DataTable

        dt = New DataTable(TableName)

        start = Convert.ToDateTime("1 " & startdate.Text)
        end1 =  Convert.ToDateTime("1 " & enddate.Text)

        flag = 1
        While start <= end1
            dt.Columns.Add(New DataColumn("ENTRADA:" & start, GetType(String)))
            dt.Columns.Add(New DataColumn("SALIDA:" & start, GetType(String)))
            dt.Columns.Add(New DataColumn("HORAS:" & start, GetType(Integer)))

            aux = ""
            aux = aux & " SELECT idclave,right(MIN(fechaEntrada),7) ENTRADA, "
            aux = aux & " right(MAX(fechaSalida),7) SALIDA, "
            aux = aux & " (datediff(n,min(fechaentrada)"
            aux = aux & " ,max(fechasalida)))/60  HORAS"
            aux = aux & " FROM(tblAsistencia)"
            aux = aux & " WHERE(CONVERT(char(10),fechaEntrada, 101) = CONVERT(char(10), DATEADD(day, - " & flag & ",CONVERT(datetime, '" & end1 & "')), 101)) "
            aux = aux & " group by idclave "

            reader = data(aux)
            reader.Read()
            dr = dt.NewRow()
            dr("ENTRADA:" & start) = reader.Item(2)
            dr("SALIDA:" & start) = reader.Item(2)
            dr("HORAS:" & start) = reader.Item(2)


            start = DateAdd(DateInterval.Day, 1, start)
            flag = flag + 1
        End While


        ' dt.Rows.Add(dr)

        Return dt
    End Function



    Public Sub ScriptError(ByVal m As String)
        'Incluye el script para mostrar los errores en el cliente
        Response.Write("<script language=""Javascript"">" & vbCrLf)
        Response.Write("window.alert('" & m & "');")
        Response.Write("history.back();")
        Response.Write("</script>")
    End Sub 'ScriptError()
    Function data(ByVal str As String) As SqlDataReader
        conn.Open()

        cmd = New SqlCommand()
        cmd.Connection = conn
        cmd.CommandTimeout = 3000
        cmd.CommandText = str
        data = cmd.ExecuteReader
    End Function
    Function data2(ByVal str As String) As SqlDataReader
        conn2.Open()

        cmd = New SqlCommand()
        cmd.Connection = conn2
        cmd.CommandTimeout = 1000
        cmd.CommandText = str
        data2 = cmd.ExecuteReader
    End Function
    Public Function conecta(ByVal str As String) As DataSet
        Try

            dataa = New SqlDataAdapter(str, connString)
            datas = New DataSet
            dataa.Fill(datas)
            conecta = datas

        Catch
        End Try

    End Function



    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        If Not IsPostBack Then


            Dim aux As String

            larea.DataTextField = "descripcion"
            larea.DataValueField = "idarea"

            larea.DataSource = conecta("select 0 as idarea,' Area' as descripcion  union select idarea,descripcion from tblarea order by descripcion").Tables(0).DefaultView
            larea.DataBind()

            lturno.DataTextField = "descripcion"
            lturno.DataValueField = "idturno"
            lturno.DataSource = conecta("select 0 as idturno,' Turno' as descripcion union select idturno,descripcion from tblturno order by descripcion").Tables(0).DefaultView
            lturno.DataBind()

            ldepto.DataTextField = "descripcion"
            ldepto.DataValueField = "idDEPTO"
            ldepto.DataSource = conecta("select 0 as iddepto,' Depto' as descripcion union select iddEPto,descripcion from tbldepto order by descripcion").Tables(0).DefaultView
            ldepto.DataBind()


            aux = " select 0 as idclave,' Supervisor' as supervisor union select idclave,(nombre+' '+apellidos) as Supervisor from tblpersonal"
            aux = aux & " where idclave in (select distinct fksupervisor from tblpersonal)"
            aux = aux & " order by supervisor"
            lsuper.DataTextField = "Supervisor"
            lsuper.DataValueField = "idclave"
            lsuper.DataSource = conecta(aux)
            lsuper.DataBind()
        End If
    End Sub


    Public Sub ScriptErrorAjax(ByVal mensaje As String)
        Dim newlinea As String

        newlinea = Environment.NewLine()
        mensaje = mensaje.Replace("'", " ").ToString().Replace("""", "")
        ScriptManager.RegisterStartupScript(Me.UpdatePanel1, GetType(String), "alertScript", "alert('" & mensaje.Replace(newlinea, "") & " ');", True)

    End Sub 

    Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click

        Try


            If enddate.Text.Length = 0 Or startdate.Text.Length = 0 Then
                ScriptErrorAjax("¡Ingrese la fecha de inicio y de fin por favor!!")
                Return
            End If

            aux2 = ""
            aux2 = aux2 & " SELECT DISTINCT personal.idclave, personal.Apellidos ,personal.Nombre ,"
            aux2 = aux2 & " depto.descripcion AREA, area.descripcion BU,Puesto, turno.descripcion TURNO,"
            aux2 = aux2 & " supervisor.apellidos + ' ' +  supervisor.nombre SUPERVISOR,personal.fkstatus,isnull(lunes,0) as lunes,isnull(martes,0) as martes,isnull(miercoles,0) as miercoles,isnull(jueves,0) as jueves,isnull(viernes,0) as viernes,isnull(sabado,0) as sabado,isnull(domingo,0) as domingo FROM tbldescanso,tblPersonal personal, tblESDLog esd, "
            aux2 = aux2 & " tbldepto Depto, tblarea area, tblusuario supervisor, tblturno turno,tblnomina nom "
            aux2 = aux2 & " where(personal.fkdepto = depto.iddepto)"
            aux2 = aux2 & " and nom.clave=personal.idclave and fksupervisor=supervisor.idclave and personal.idclave = tbldescanso.idclave and"
            aux2 = aux2 & " fkarea=idarea and idturno=fkturno and "

            If cbaja.Checked Then

                aux2 = aux2 & " (fkstatus<>'1' or personal.idclave in"
                aux2 = aux2 & " ("
                aux2 = aux2 & " select empleado from tblpermisos where  razon='BJA'"
                aux2 = aux2 & " and fecha between (dateadd(dd,-30,(select getdate() ))) and (select getdate())"
                aux2 = aux2 & " )"
                aux2 = aux2 & ")"
            Else
                aux2 = aux2 & " (fkstatus<>'1')"
            End If


            If Lnomina.SelectedValue <> 0 Then
                aux2 = aux2 & " and fktipo in ( " & Lnomina.SelectedValue & ")"
            End If

            If fknom.SelectedValue <> 0 Then
                aux2 = aux2 & " and tipo in ( " & fknom.SelectedValue & ")"
            End If

            If txempleado.Text <> "" Then
                aux2 = aux2 & " and personal.idclave=" & txempleado.Text
            End If
            If TXNOMBRE.Text <> "" Then
                aux2 = aux2 & " and personal.nombre like '%" & TXNOMBRE.Text & "%'"
            End If
            If txapellido.Text <> "" Then
                aux2 = aux2 & " and personal.apellidos like '%" & txapellido.Text & "%'"
            End If
            If Txpuesto.Text <> "" Then
                aux2 = aux2 & " and personal.puesto like '%" & Txpuesto.Text & "%'"
            End If
            If larea.SelectedValue <> 0 Then
                aux2 = aux2 & " and fkarea=" & larea.SelectedValue
            End If
            If lturno.SelectedValue <> 0 Then
                aux2 = aux2 & " and fkturno=" & lturno.SelectedValue
            End If
            If lsuper.SelectedValue <> 0 Then
                aux2 = aux2 & " and fksupervisor=" & lsuper.SelectedValue
            End If
            If ldepto.SelectedValue <> 0 Then
                aux2 = aux2 & " and fkdepto=" & ldepto.SelectedValue
            End If

            start = startdate.Text
            end1 = enddate.Text

            flag = DateDiff(DateInterval.Day, start, end1)
            flag2 = flag
            Dim sel As String


            While start <= end1
                aux = ""

                aux = aux & " select a.idclave,isnull(razon,entrada)ENTRADA,isnull(razon,salida) SALIDA,isnull(Horas,0)HORAS from ( "
                aux = aux & " select p.idclave,b.entrada,b.salida,b.horas from (select distinct idclave from tblpersonal) p "
                aux = aux & " left outer join ("
                aux = aux & " SELECT  idclave,right(MIN(fechaEntrada),7) ENTRADA,"
                aux = aux & " right(MAX(fechaSalida),7) SALIDA,  (datediff(n,min(fechaentrada), max(fechasalida)))/60  HORAS "
                aux = aux & " FROM tblAsistencia  WHERE(CONVERT(char(10),fechaEntrada, 101) = CONVERT(char(10), "
                aux = aux & " DATEADD(day, -0,CONVERT(datetime, '" & start & "')), 101))  group by idclave ) b "
                aux = aux & " on p.idclave=b.idclave ) a "
                aux = aux & " left outer join "
                aux = aux & " (select p.idclave,fecha,c.razon"
                aux = aux & " from (select distinct idclave from tblpersonal) p "
                aux = aux & " left outer join (select * from  tblpermisos) c"
                aux = aux & " on p.idclave=c.empleado"
                aux = aux & " where CONVERT(char(10),fecha, 101) = CONVERT(char(10), DATEADD(day, -0,CONVERT(datetime, '" & Format(start, "yyyy-MM-dd") & "')), 101) "
                aux = aux & " ) b on b.idclave=a.idclave "

                sql = ""
                If start <> end1 Then

                    aux3 = aux3 & ",[ENTRADA:" & start & "],"
                    aux3 = aux3 & "[SALIDA:" & start & "],"
                    aux3 = aux3 & "[HORAS:" & start & "]"
                    sql = sql & "select DATOS.*"
                Else
                    sql = " Select datos.idclave,datos.apellidos,datos.nombre,datos.area,datos.bu,puesto,datos.turno,datos.supervisor,datos.fkstatus" & aux3
                End If

                sql = sql & " ,isnull(A.ENTRADA,case "
                sql = sql & " when datepart(dw,'" & start & "')=2 and datos.lunes=1  then 'DESC'"
                sql = sql & " when datepart(dw,'" & start & "')=3 and datos.martes=1 then 'DESC'"
                sql = sql & " when datepart(dw,'" & start & "')=4 and datos.miercoles=1 then 'DESC'"
                sql = sql & " when datepart(dw,'" & start & "')=5 and datos.jueves=1 then 'DESC'"
                sql = sql & " when datepart(dw,'" & start & "')=6 and datos.viernes=1 then 'DESC'"
                sql = sql & " when datepart(dw,'" & start & "')=7 and datos.sabado=1 then 'DESC'"
                sql = sql & " when datepart(dw,'" & start & "')=1 and datos.domingo=1 then 'DESC'"
                sql = sql & " else 'NOCHECO' end) AS 'ENTRADA:" & start & "'"

                sql = sql & ",isnull(A.SALIDA,case "
                sql = sql & " when datepart(dw,'" & start & "')=2 and datos.lunes=1  then 'DESC'"
                sql = sql & " when datepart(dw,'" & start & "')=3 and datos.martes=1 then 'DESC'"
                sql = sql & " when datepart(dw,'" & start & "')=4 and datos.miercoles=1 then 'DESC'"
                sql = sql & " when datepart(dw,'" & start & "')=5 and datos.jueves=1 then 'DESC'"
                sql = sql & " when datepart(dw,'" & start & "')=6 and datos.viernes=1 then 'DESC'"
                sql = sql & " when datepart(dw,'" & start & "')=7 and datos.sabado=1 then 'DESC'"
                sql = sql & " when datepart(dw,'" & start & "')=1 and datos.domingo=1 then 'DESC'"

                sql = sql & " else 'NOCHECO' end) AS 'SALIDA:" & start & "',"
                sql = sql & " isnull(A.HORAS,0) AS 'HORAS:" & start & "'"
                sql = sql & " from ("
                sql = sql & aux2
                sql = sql & ")datos LEFT OUTER JOIN ("
                sql = sql & aux
                sql = sql & ") A ON DATOS.IDCLAVE=A.idclave "

                aux2 = sql

                flag = flag - 1
                start = DateAdd(DateInterval.Day, 1, start)
            End While

            '  dt = conecta(aux).Tables(0)

            sql = sql

            ' Dim tabla As DataTable
            '[ tabla = conecta(sql).Tables(0)
            Grid1.Columns.Clear()

            Grid1.DataSource = data(sql)
            Grid1.DataBind()


            conn.Close()
            color(flag2)


        Catch ex As Exception
            ScriptErrorAjax(ex.Message)
        End Try


    End Sub

    Protected Sub Button2_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button2.Click

        excelexp()


    End Sub

    Sub color(ByVal z As Integer)
        Dim x As Integer = 1
        Dim y As Integer = 1
        Dim a As Array
        Dim b As String
        Dim colore As Integer = 0
        Dim pbaja As Date
        Dim fact As Array

        For x = 0 To Grid1.Rows.Count - 1
            If (Grid1.Rows(x).Cells(8).Text = "1") Then
                Grid1.Rows(x).BackColor = Drawing.Color.Yellow
                fbaja = data2("select fecha from tblpermisos where  razon = 'BJA' and empleado ='" & Grid1.Rows(x).Cells(0).Text & "'")
                fbaja.Read()
                pbaja = CDate(fbaja(0))
                conn2.Close()
            End If
            For y = 9 To (z * 3) + 9 Step 3
                If (Grid1.Rows(x).Cells(y).Text <> "NOCHECO") Then
                    a = (Grid1.Rows(x).Cells(y).Text).Substring(1, Grid1.Rows(x).Cells(y).Text.Length - 3).Split(":")
                    b = Grid1.Rows(x).Cells(y).Text
                    ' If ((a(0) >= 6 And a(0) < 9) And Grid1.Rows(x).Cells(5).Text = "MATUTINO") Then
                    If (Grid1.Rows(x).Cells(y).Text = "VAC") _
                Or (Grid1.Rows(x).Cells(y).Text.Substring(0, 3) = "PCG") _
                Or (Grid1.Rows(x).Cells(y).Text.Substring(0, 3) = "PSG") _
                Or (Grid1.Rows(x).Cells(y).Text.Substring(0, 3) = "SUS") _
                Or (Grid1.Rows(x).Cells(y).Text.Substring(0, 3) = "INC") _
                Or (Grid1.Rows(x).Cells(y).Text.Substring(0, 3) = "DES") _
                Or (Grid1.Rows(x).Cells(y).Text.Substring(0, 3) = "COM") _
Or (Grid1.Rows(x).Cells(y).Text.Substring(0, 3) = "BJA") _
Or (Grid1.Rows(x).Cells(y).Text.Substring(0, 3) = "BAJ") Then

                        If (Grid1.Rows(x).Cells(y).Text.Substring(0, 3) <> "BJA") Then
                            Grid1.Rows(x).Cells(y).BackColor = Drawing.Color.White
                            Grid1.Rows(x).Cells(y + 1).BackColor = Drawing.Color.White
                            Grid1.Rows(x).Cells(y + 2).BackColor = Drawing.Color.White
                        End If
                        ' Grid1.Rows(x).Cells(y).BackColor = Drawing.Color.LightGreen
                        ' Grid1.Rows(x).Cells(y + 1).BackColor = Drawing.Color.LightGreen
                        ' Grid1.Rows(x).Cells(y + 2).BackColor = Drawing.Color.LightGreen


                    Else
                        If (Grid1.Rows(x).Cells(y).Text.Substring(0, 3) <> "FTA") Then

                            If (CDate(b) >= CDate("6:01AM") And CDate(b) < CDate("12:00PM")) And ((Grid1.Rows(x).Cells(6).Text = "MATUTINO") Or (Grid1.Rows(x).Cells(6).Text = "ESPECIAL 8") Or (Grid1.Rows(x).Cells(6).Text = "ESPECIAL 9")) Then
                                Grid1.Rows(x).Cells(y).BackColor = Drawing.Color.LightCoral
                                Grid1.Rows(x).Cells(y + 1).BackColor = Drawing.Color.LightCoral
                                Grid1.Rows(x).Cells(y + 2).BackColor = Drawing.Color.LightCoral

                            ElseIf (CDate(b) >= CDate("12:01PM") Or CDate(b) < CDate("5:00AM")) And (Grid1.Rows(x).Cells(6).Text = "MATUTINO") Then
                                ' Grid1.Rows(x).Cells(y).BackColor = Drawing.Color.LightBlue
                                ' Grid1.Rows(x).Cells(y + 1).BackColor = Drawing.Color.LightBlue
                                ' Grid1.Rows(x).Cells(y + 2).BackColor = Drawing.Color.LightBlue

                            ElseIf (CDate(b) >= CDate("2:01PM") And CDate(b) < CDate("6:00PM")) And (Grid1.Rows(x).Cells(6).Text = "VESPERTINO") Then
                                Grid1.Rows(x).Cells(y).BackColor = Drawing.Color.LightCoral
                                Grid1.Rows(x).Cells(y + 1).BackColor = Drawing.Color.LightCoral
                                Grid1.Rows(x).Cells(y + 2).BackColor = Drawing.Color.LightCoral

                            ElseIf (CDate(b) >= CDate("6:01PM") Or CDate(b) < CDate("1:00PM")) And ((Grid1.Rows(x).Cells(6).Text = "VESPERTINO") Or (Grid1.Rows(x).Cells(5).Text = "ESPECIAL 10") Or (Grid1.Rows(x).Cells(5).Text = "ESPECIAL 11")) Then
                                Grid1.Rows(x).Cells(y).BackColor = Drawing.Color.LightCoral
                                Grid1.Rows(x).Cells(y + 1).BackColor = Drawing.Color.LightCoral
                                Grid1.Rows(x).Cells(y + 2).BackColor = Drawing.Color.LightCoral

                            ElseIf (CDate(b) >= CDate("9:31PM") And CDate(b) < CDate("11:59PM")) And (Grid1.Rows(x).Cells(6).Text = "NOCTURNO") Then
                                Grid1.Rows(x).Cells(y).BackColor = Drawing.Color.LightCoral
                                Grid1.Rows(x).Cells(y + 1).BackColor = Drawing.Color.LightCoral
                                Grid1.Rows(x).Cells(y + 2).BackColor = Drawing.Color.LightCoral

                            ElseIf (CDate(b) < CDate("8:01PM")) And (Grid1.Rows(x).Cells(6).Text = "NOCTURNO") Then
                                'Grid1.Rows(x).Cells(y).BackColor = Drawing.Color.LightBlue
                                ' Grid1.Rows(x).Cells(y + 1).BackColor = Drawing.Color.LightBlue
                                '  Grid1.Rows(x).Cells(y + 2).BackColor = Drawing.Color.LightBlue

                            End If
                        Else
                            Grid1.Rows(x).Cells(y).BackColor = Drawing.Color.LightCoral
                            Grid1.Rows(x).Cells(y + 1).BackColor = Drawing.Color.LightCoral
                            Grid1.Rows(x).Cells(y + 2).BackColor = Drawing.Color.LightCoral
                        End If
                    End If

                    If (Grid1.Rows(x).Cells(8).Text = "1") Then
                        fact = Grid1.HeaderRow.Cells(y).Text.Split(":")

                        If (pbaja <= CDate(fact(1))) And ( _
                     (Grid1.Rows(x).Cells(y).Text = "VAC") _
                Or (Grid1.Rows(x).Cells(y).Text.Substring(0, 3) = "PCG") _
                Or (Grid1.Rows(x).Cells(y).Text.Substring(0, 3) = "PSG") _
                Or (Grid1.Rows(x).Cells(y).Text.Substring(0, 3) = "SUS") _
                Or (Grid1.Rows(x).Cells(y).Text.Substring(0, 3) = "INC") _
                Or (Grid1.Rows(x).Cells(y).Text.Substring(0, 3) = "DES") _
                Or (Grid1.Rows(x).Cells(y).Text.Substring(0, 3) = "COM")) Then


                            Grid1.Rows(x).Cells(y).Text = "BAJA"
                            Grid1.Rows(x).Cells(y + 1).Text = "BAJA"
                            Grid1.Rows(x).Cells(y).BackColor = Drawing.Color.Yellow
                  Grid1.Rows(x).Cells(y + 1).BackColor = Drawing.Color.Yellow
                            Grid1.Rows(x).Cells(y + 2).BackColor = Drawing.Color.Yellow
                        Else
                            If (Grid1.Rows(x).Cells(y).Text.Substring(0, 3) = "BJA") Then
                                Grid1.Rows(x).Cells(y).BackColor = Drawing.Color.Yellow
                                Grid1.Rows(x).Cells(y + 1).BackColor = Drawing.Color.Yellow
                                Grid1.Rows(x).Cells(y + 2).BackColor = Drawing.Color.Yellow

                            Else
                                Grid1.Rows(x).Cells(y).BackColor = Drawing.Color.LightCoral
                                Grid1.Rows(x).Cells(y + 1).BackColor = Drawing.Color.LightCoral
                                Grid1.Rows(x).Cells(y + 2).BackColor = Drawing.Color.LightCoral

                            End If

                        End If
                    End If
                Else

                    If (Grid1.Rows(x).Cells(8).Text = "1") Then
                        fact = Grid1.HeaderRow.Cells(y).Text.Split(":")

                        If pbaja <= CDate(fact(1)) Then


                            Grid1.Rows(x).Cells(y).Text = "BAJA"
                            Grid1.Rows(x).Cells(y + 1).Text = "BAJA"
                            Grid1.Rows(x).Cells(y).BackColor = Drawing.Color.Yellow
                            Grid1.Rows(x).Cells(y + 1).BackColor = Drawing.Color.Yellow
                            Grid1.Rows(x).Cells(y + 2).BackColor = Drawing.Color.Yellow
                        Else
                            Grid1.Rows(x).Cells(y).BackColor = Drawing.Color.LightCoral
                            Grid1.Rows(x).Cells(y + 1).BackColor = Drawing.Color.LightCoral
                            Grid1.Rows(x).Cells(y + 2).BackColor = Drawing.Color.LightCoral
                        End If
                    Else
                        Grid1.Rows(x).Cells(y).BackColor = Drawing.Color.LightCoral
                        Grid1.Rows(x).Cells(y + 1).BackColor = Drawing.Color.LightCoral
                        Grid1.Rows(x).Cells(y + 2).BackColor = Drawing.Color.LightCoral
                    End If



                End If



            Next


        Next
    End Sub

    Sub excelexp()
        Dim sb As StringBuilder = New StringBuilder()
        Dim SW As System.IO.StringWriter = New System.IO.StringWriter(sb)
        Dim htw As HtmlTextWriter = New HtmlTextWriter(SW)
        Dim Page As Page = New Page()
        Dim form As HtmlForm = New HtmlForm()
        Grid1.EnableViewState = False
        Page.EnableEventValidation = False
        Page.DesignerInitialize()
        Page.Controls.Add(form)
        form.Controls.Add(Grid1)
        Page.RenderControl(htw)
        Response.Clear()
        Response.Buffer = True
        Response.ContentType = "application/vnd.ms-excel"
        Response.AddHeader("Content-Disposition", "attachment;filename=asistencia.xls")
        Response.Charset = "UTF-8″"
        Response.ContentEncoding = Encoding.Default
        Response.Write(sb.ToString())
        Response.End()
    End Sub

    Protected Sub Button3_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button3.Click
        txempleado.Text = ""
        TXNOMBRE.Text = ""
        txapellido.Text = ""
        startdate.Text = ""
        enddate.Text = ""
        lsuper.SelectedValue = 0
        larea.SelectedValue = 0
        lturno.SelectedValue = 0
        ldepto.SelectedValue = 0
        Grid1.DataSource = ""
        Grid1.DataBind()
    End Sub



End Class