<script runat="server">Sub user(source As object,args As ServerValidateEventArgs) if len(args.Value)<8 or len(args.Value)>16 then args.IsValid=false else args.IsValid=true end ifEnd Sub</script> <html><body><form runat="server"><asp:Label runat="server" Text="Enter a username: " /><asp:TextBox id="txt1" runat="server" /><asp:Button Text="Submit" runat="server"/><br /><asp:Label id="mess" runat="server"/><br /><asp:CustomValidatorControlToValidate="txt1"OnServerValidate="user"Text="A username must be between 8 and 16 characters!"runat="server"/></form></body></html>
