button loading animated gif

it's a simple task: I need a script that adds a loading animated gif to a button. I need to run this script on a long row of buttons in the same menu div. it doesn't actually need to check for percent loaded, I just want the user to know that the page is loading and I want this gif to play for 5 seconds and then fade out. it is urgent and easy , so please give your best offer asap. I need it in a few hours.