Therefore, you also have to make sure that the values that users enter can be correctly converted to the appropriate data types.You might also have certain restrictions on the values.These pairs let you define rules for both conditions: an error condition and a "normal" (non-error) condition.It's important to understand that the markup for the error display is always rendered, even if there are no errors.Many people are asking me how to validate Grid View with Java Script. This article and attached code snippet shows you to create a validate method in Java Script and call it from your ASP. Thid methods finds each control in a Grid View row using get Element By Id as an object and then checks if it is checked or not and so on. As you can see on this page, on page's Load event handler, I add an attribute to the button's click event hander onclick and call Java Script's validate method whenever a button is clicked. As you can see in the below code, I have a validate method.
To see how validation works, run this page and deliberately make mistakes.For example, here's what the page looks like if you forget to enter a course name, if you enter an, and if you enter an invalid date: By default, user input is validated after users submit the page — that is, the validation is performed in server code.