Hi,

This is what I want to accomplish:

I'd like to display a small image/icon beside a text box when it passes the validation.

For example: I have a text box named txtFirstName. It is a required field. If  it is not being filled in,  I would like to display a small "error.gif" image next to  the text box. If it successfully filled in. A
different icon will be displayed.

Can anyone suggest how to work on something like this?

Take a look at this page and download the sample code: http://www.askthecssguy.com/examples/validationhints/formfieldhints.html
It shouldn't be that hard to adjust the script to only show icons. 

ASP.NET Validators do not support that capability. I suspect you can create a hack with javascript to do it. You probably will hook up to the textbox's onblur event. Then evaluate the list of validators in Page_Validators to find those assigned to your textbox. Look at the IsValid property of each matching validator. Finally, change the style on an image already placed to the right of the textbox. style="display:inline;" shows it. display:none; hides it.

FWIW: My replacement validators for ASP.NET handle this. Each validator has a property called NoErrorFormatter which determines the appearance and rules for displaying when the validator is hidden.

Thanks a lot!  I will try both.