Validating forms in asp
As you see, it's very simple - just check the Page. Try to run the website again, and notice how the text of the button is changed if you submit a valid form.
For that reason, it is important that you verify that the data entered from your users is, at minimum, in the correct format.
This process is known as form validation and can occur in two places: through client-side scripting code on the user's browser (known as client-side form validation) and on an ASP page before submitting the data to the database (known as server-side form validation).
Right now, the button does nothing, besides posting back if the page is valid.
We will change this by adding an onclick event to it: As you will notice, we check whether or not the page is valid, before we do anything.
To create a validation group, you should put the input controls and the validation controls into the same logical group by setting their Validation Group property.
The following example describes a form to be filled up by all the students of a school, divided into four houses, for electing the school president.
Most often, the purpose of data validation is to ensure correct user input.
Validation can be defined by many different methods, and deployed in many different ways.
The server side validation routine should be written in any . The summary displays the values of the Error Message property of all validation controls that failed validation.