I am quite new to magento. Can you suggest a tutorial for using ajax in magento? I checked this but couldn't find a step by step tutorial for newbies like me. My requirement is, I need to check availability of the username when user enters a "username", without refreshing the page. I want to sent the entered username to a controller and check if it's already used, and sent back a message to the user reg its availability. Pls help me in achieving this using ajax.