If you are using ASP.NET Validation Control then you can use “SetFocusOnError” properties to automatically focus the control if validation fails. This will help the end user to identify the control easily.
To set focus automatically you have to set SetFocusOnError=”True”. By default it’s false. SetFocusOnError of a validation control is associated with “ControlToValidate” properties. If the validation fails, focus will automatically move to the control which is specified in ControlToValidate.