Is there an event?

I have some Javascript that is triggered by an onclick event on a dummy link.  It fades pictures in and out, works fine, but I would like the page to do this automatically when displayed, not requiring a user to do anything, the pictures just fade in and out on their own.

Is there any event in the event list that can do this or is there some clock mechanism that has to be coded in Javascript to keep firing off the function?

Jim