Shahid Online - Tech Corner

One of the most popular uses of Javascript is when it comes to validating user input on a form. The most hateful way, though, is by not using onsubmit. A number of times I come across code where someone uses an image in place of the submit button and uses the onclick event which will validate then submit the form. Yeauch! Very bad practice! The first thing to do with the form is place the Javascript function in the onsubmit attribute for the form, e.g. <form name="reg" method="post" onsubmit="return validateForm();" The use of return lets the form submit when the function returns true. If the function does not return true (i.e. false) then the form will not submit - as shown below. function validateForm(){ return false; } Getting a reference to the form is the next step. There are a number of ways to do this: document.forms[0] document.forms['reg'] document.getElementById('reg') This will work when id is used on the form Passing an o...