you can buy one at walmart for $20 I believe

The belt came off again today. But right before it happend i drove thru some puddles so do belts just slide off when they are wet?

Belts do not come off when they get wet. You probably have a bad pulley. It is often the idler pulley on the tensioner assembly that goes bad. If so, they can be replaced for about $20 iirc. With the belt off, grab hold of all the pulleys and see which one (if any) wiggles. Sight down the pulleys and see if any are out of line. Replace the bad pulley (or component) and your belt will stay on.

I thought you just put new pulley on? Your tensioner might be shot. Can you get a picture of it with the belt on to see where the little arrow points to on the tensioner? I still have that one if you want it

We put it back on last night and it has been fine. If it comes off again ill pm you haro.