Here is a small example to show you how to validate a DropDownList using RequiredFieldValidator:
<form id="Form1" method="post" runat="server">
<asp:DropDownList id="DropDownList1" runat="server">
<asp:ListItem Value="-1">--> Choose <--<asp:ListItem>
<asp:ListItem Value="1">Lebanon</asp:ListItem>
<asp:ListItem Value="2">Kuwait</asp:ListItem>
</asp:DropDownList>
<asp:RequiredFieldValidator id="RequiredFieldValidator1"
runat="server" ErrorMessage="You must select a valid option"
ControlToValidate="DropDownList1" InitialValue="-1"
Display="Dynamic" />
<P>
<asp:Button id="Button1" runat="server" Text="Post Back" />
<P>
<form>
Hope this helps,
Regards
Tags: