Some users are not interested in spending enough time to enter the correct information into a form, and in some cases, users might even intentionally enter false information to gain access or get past a certain step in your application's workflow process.
One of the first steps is to understand what validating data means.
The bad thing about server-side validation is that it requires trips back and forth to the server.
This takes a lot of resources and makes for a slower-paced form for the user.
Some sites on the Internet don't carry this inputted information back to the form page, and the user is then required to enter all the information into the form a second time.
(34 printed pages) Introduction Looking at Validation The Required Field Validator Control The Compare Validator Control The Range Validator Control The Regular Expression Validator Control The Custom Validator Control The Validation Summary Control Conclusion In your studies of ASP.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.Nothing is more annoying to a user who is on a dial-up connection than clicking the Submit button on the form and then waiting for 20 seconds to find out that they didn't enter their password correctly.
The other option for form validation is to put some client-side Java Script or VBScript at the top of the ASP page that checks if the information in the fields is correct.If the data is incorrect or not valid, you can send back a response stating this.