An important aspect of creating Web Forms pages for user input is to be able to check that the information users enter is valid. The Web Forms framework provides a set of validation controls that provide an easy-to-use but powerful way to check for errors, and if necessary, display messages to the user.
The following topics tell you more about validation controls and how to use them.
Introduction to Validating User Input in Web Forms
Validating Against a Specific Value
Validating Against a Data Type
Validating Against Values in a Database
Validating Against a Range of Values
Validating with a Custom Function
Testing Validity Programmatically
Controlling Validation Error Message Display
Formatting Validation Error Messages
Specifying Layout for In-Place Messages
Disabling Validation at Run Time
Displaying Custom Error Messages
Enhancing or Replacing Client-Side Validation
Allowing Posting with Client-Side Validation Errors
Controlling Client versus Server Validation
See Also