Dirty Forms

Prevent users from losing data when editing forms:

Dirty Forms is a flexible jQuery plugin to help prevent users from losing data when editing forms.Dirty Forms will alert a user when they attempt to leave a page without submitting a form they have entered data into.

Prerequisites

Must have jQuery Library version 1.4.2 or higher.

download JQuery Dirtyforms.js file here...  

easy to use.

<script type="text/javascript" src="http://mal.co.nz/wp-content/themes/boldy/js/jquery-1.4.2.min.js"></script>

<script type="text/javascript" src="jquery.dirtyforms.js"></script>
<script type="text/javascript">

$(document).ready(function(){

      $('#testform').dirtyForms();
 
 $('#dirtycheck').click(function(){
 if($.DirtyForms.isDirty()){
 alert("Your form is so dirty...");
 }else{
 alert("Your form is a saint, nothing dirty about her");
 }
    });

});
</script>

<form id="testform">
<input type="text" value="Change me to make me dirty" />
<input id="dirtycheck" type="button" value="Am I dirty?" />
</form>

Public Methods

$.DirtyForms.isDirty() will return true if any watched elements are considered dirty. 
Syntax: if($.DirtyForms.isDirty())