Validation server controls are a series of controls that help you validate the data that the user enters into the other controls that are provided with ASP. They determine whether the form can be processed based upon the rules that you define in the validation server controls.One of the most common elements of Web pages is a form in which the user can input data that is posted back to the server.
But even if the framework provides different kinds of validators, there are so many different validations patterns that sometimes you have to write custom code to match your specific requirements.
(16 printed pages) Introduction Getting Started Writing the Validation Script Connecting the Form to the Script Associating Form Fields with Custom Script Code Listing Conclusion When you create forms, providing form validation is useful to ensure that your customers enter valid and complete data.
For example, you may want to ensure that someone inserts a valid e-mail address into a text box, or perhaps you want to ensure that someone fills in certain fields.
Server-side validation incorporates code validation into a form handler. NET application on the server that provides the functionality that your form needs for processing after a customer has submitted it.
Because the code is stored on the server, server-side validation requires a roundtrip to the server.
I wrote a post a few months ago about how to write a custom validator for a Checkbox list, but I was dealing with a completely new validation pattern.