<telerik:RadComboBox ID="RadComboBoxTables" Runat="server"

DataSourceID="ObjectDataSourceMetaDateTables" DataTextField="Name"

DataValueField="Name" Label="Table: "

ondatabound="Tables_DataBound"

onitemsrequested="Tables_ItemsRequested"

OnClientSelectedIndexChanging="metaDataTableSelected"

LabelCssClass="riLabel" Width="100%"

EmptyMessage="- Select table - "

ValidationGroup="AttrValidationGroup">

</telerik:RadComboBox>

I tried doing  this 2 ways:

1. I used a CompareValidator..This should display the error message if the user does not select a table; however, no error message is displayed. If select -Select table - from RadComboBox again, no error is displayed.  Is/Can the EmptyMessage be used here as the value to compare to?

(NOTE: if I change the Operator to Operator=Equal, then it displays the error if user doesn't select anything, selects a table, or selects "- Select table - " from RadComboBox.)

//CompareValidator:

<asp:CompareValidator

ID="CompareValidatorRadComboxBoxTables"

runat="server"

ValueToCompare=" - Select table - "

Operator="NotEqual"

ControlToValidate="RadComboBoxTables"

ErrorMessage="Please select Table..."

ValidationGroup="AttrValidationGroup">

</asp:CompareValidator>

I also tried using the Requiredfield Validator like a saw in an example on this site (http://demos.telerik.com/aspnet-ajax/combobox/examples/default/defaultcs.aspx  this example worked fine), but no error was displayed for my app.

//RequiredFieldValidator:

<asp:RequiredFieldValidator ID="RequiredFieldValidatorComboTxtBxTables"

runat="server"

ControlToValidate="RadComboBoxTables"

ErrorMessage="Please select table from list..."

ValidationGroup="AttrValidationGroup">

</asp:RequiredFieldValidator>