For an alternative approach to client-side form validation, without Java Script, check out our new article on HTML5 Form Validation which is available now in most modern browsers.When form input is important, it should always be verified using a secure server-side script.I've coded a working form, all checks are great but for some reason the hardest part is trying to stop form submission before validation.So i have places to insert the stop validation code, but just cant find any that works.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.
That could be done using Ajax, but would make the CAPTCHA much easier to break.
It makes your page much more user-friendly, and takes out the frustration of having to fill out the same form repeatedly.
It's also very precise, as you can point out the exact field where there's a problem.
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.
You'll see that the all validation scripts presented on this and subsequent pages adhere to the same basic format.