Validating form input with Java Script is easy to do and can save a lot of unnecessary calls to the server as all processing is handled by the web browser.
It can prevent people from leaving fields blank, from entering too little or too much or from using invalid characters.
This tutorial will show you how to create a Java Script-enabled form that checks whether a user has filled in the form correctly before it's sent to the server. First we'll explain why form validation is a useful thing, and then build up a simple example form, explaining things as we go along.
At the end, there's a little exercise to keep you busy too!
We're going to be checking the form using a function, which will be activated by the form's Validating this form would be considerably simpler than one containing radio buttons or select boxes, but any form element can be accessed.
Below are the ways to get the value from all types of form elements.
Introduction A developer is asking how to select one radio button at a time if the radio button is inside the Grid View.
As you may know setting the group name attribute of a radio button will not work if the radio button is located within a data representation control like a Grid View.
Other form values are available using a similar syntax, although this becomes more complicated if you're using SELECT lists, checkboxes or radio buttons (see below for examples). All you need to do is extend the command is encountered, execution of the function is halted.This is because the radio button inside a Grid View behaves differently.Since a Grid View is rendered as a table element, at run time it will assign a different "name" to each radio button. In this article I'm going to show how to select one radio button at a time in Grid View and add a simple validation to it using plain Java Script.A Java Script check is useful because it stops the form from being submitted if there is a problem, saving lots of time for your readers.The CGI script is still more reliable, as it always works regardless of whether Java Script is enabled on the client-side or not; but having this extra safety barrier is a nice thing to have in place.