Most of the time we used simple text messages for error notifications when ASP.NET validator control fails the validation. But the interesting things with ASP.NET validation controls is instead of simple text we can display images as error notification. Not only images we can embed sounds or we can display some html format text as well.
To achieve instead of setting
ErrorMessage property of an Validation control, you need to set
Text Property with proper HTML content.
Not only images, you can also display additional information as an html content or normal text message.