如何使用jQuery每5秒钟生成一个动画？

Okay so I don't have much experience with jQuery. What I'm trying to do here is make the background of the page change every 5 seconds (10 seconds actually but 5 is for testing). Along with this I want a countdown animation, like a bar below on the page. I've got the background changing every 5 seconds but I cant get the bar animations working. It only occurs once or twice but then never happens again ://// Okay so I don't have much experience with jQuer