How to Check a Selection in Dropdown using ASP.NET Validation | Dropdown Client Validation ASP.NET

This Example illustrate that how to check if any value is selected in dropdown  or not. This validation is totally perform on client site using asp.net RequiredFieldValidator.  just specify  ControlToValidate as dropdown name and InitialValue as whatever dropdown initial value is.

 

<asp:dropdownlist id="cmbDemo" runat=server>

<asp:listitem>Select</asp:listitem>

<asp:listitem >Demo1</asp:listitem>

<asp:listitem >Demo2</asp:listitem>

<asp:listitem >Demo3</asp:listitem>

</asp:dropdownlist>

<asp:RequiredFieldValidator ControlToValidate="cmbDemo" InitialValue="Select" errormessage="You must select a value" runat=server/>

<asp:button type=submit text="Click" runat="server"/>