I have a problem I am using jqxwidget and I need to validate that a field is required, and I must do it from javascript because it will be required depending on what is selected in other components, here my html code:
<div id="divPlaza" class="col-sm-4 pc-sig-UsuarioPuestoId pc-sig-
UsuarioRolId" style="display: block;">
<label>Plaza:</label><span class="obligatorio">*</span><br
style="clear:both"><div id="UsuarioPlazaId" class="campoComboBusq pc-
campo pc-sig-UsuarioPuestoId pc-sig-UsuarioRolId jqx-combobox-state-
normal jqx-combobox-state-normal-office jqx-combobox jqx-combobox-office
jqx-rc-all jqx-rc-all-office jqx-widget jqx-widget-office jqx-widget-
content jqx-widget-content-office" role="combobox" aria-
autocomplete="both" aria-disabled="false" aria-
owns="listBoxjqxWidgetf77b8083" aria-haspopup="true" aria-
multiline="false" style="height: 25px; width: 90%;" aria-
readonly="false"><div style="background-color: transparent; -webkit-
appearance: none; outline: none; width:100%; height: 100%; padding: 0px;
margin: 0px; border: 0px; position: relative;"><div
id="dropdownlistWrapperUsuarioPlazaId" style="padding: 0; margin: 0;
border: none; background-color: transparent; float: left; width:100%;
height: 100%; position: relative;"><div
id="dropdownlistContentUsuarioPlazaId" style="padding: 0px; margin: 0px;
border-top: none; border-bottom: none; float: left; position: absolute;
width: 272px; height: 25px; left: 0px; top: 0px;" class="jqx-combobox-
content jqx-combobox-content-office jqx-widget-content jqx-widget-
content-office"><input autocomplete="off" style="margin: 0px; padding:
0px; border: 0px; width: 100%; height: 25px;" type="textarea" class="jqx-
combobox-input jqx-combobox-input-office jqx-widget-content jqx-widget-
content-office jqx-rc-all jqx-rc-all-office" value=""
placeholder="SELECCIONA UNA OPCIÓN"></div><div
id="dropdownlistArrowUsuarioPlazaId" role="button" style="padding: 0px;
margin: 0px; border-width: 0px 0px 0px 1px; float: right; position:
absolute; width: 19px; height: 25px; left: 273px;" class="jqx-combobox-
arrow-normal jqx-combobox-arrow-normal-office jqx-fill-state-normal jqx-
fill-state-normal-office jqx-rc-r jqx-rc-r-office"><div class="jqx-icon-
arrow-down jqx-icon-arrow-down-office jqx-icon jqx-icon-office"></div>
</div></div></div><input type="hidden" value=""></div><div
id="btnBusqPlaza" class="glyphicon glyphicon-search busqueda"
tabindex="0" title="Busqueda de Plaza"></div></div>