Client Scripting

Prevent User Navigating Away from Page with Unsaved Changes
When a user is editing data on a web page and they navigate to another page before saving that data, their changes will be lost. Here's some handy jQuery to warn the user any time they attempt to navigate to another page with unsaved changes and give them the option of staying on the current page to save those changes.
By Jonathan Wood on Saturday, August 06, 2011