ERRor message in Required field validator in asp.net

I am having problem with required field validator. I want to display validation error message immediately on form when textbox left empty and not after clicking on submit button.

 

Read http://www.aspdotnetfaq.com/Printer...s-Client-Side-validation-from-JavaScript.aspx (and the link it has to the microsoft page) and it gives you the javascript to call the validation client side

 

If you use the requiredfieldvalidator control of the asp.net the error message will show you immediately you left the the textbox with blank. If you don't want the error message to come in the submit button you can disable the "cause validation" property of the button to false.