i have used custom validator
protected void cvIsActive_ServerValidate(object source,ServerValidateEventArgs args)
{
if(args.Value.Length==1)
args.IsValid = true;
else
args.IsValid = false;
}
this is code for server validate.. i have written to check whether its checked or not. i have taken control to validate as checkbox
<asp:CustomValidator runat="server" ErrorMessage="Please Select Status"
ID="cvIsActive" Font-Size="Smaller"
onservervalidate="cvIsActive_ServerValidate" ControlToValidate="chkIsActive"></asp:CustomValidator>
but as soon as page loads it giving error
Control 'chkIsActive' referenced by the ControlToValidate property of 'cvIsActive' cannot be validated.