A clickable div that creates an AsyncPostback and triggers an update panel

I would like to create a 300x300 div that is clickable, and sends an ajax post back to the page and resulls an update panel to update (Kind of like an aspx button control), by using the getPostBackEvent reference i get the code tht will result in a post back, but it wont post it back Asyncronusly.

Source Click Here.