JS: Help with a Switching Function (possible?)

I have a DIV with with a background which has an arrow facing down on it. I have another image which has an arrow pointing right.

What I’m trying to do, is when I click on the DIV, the DIV’s background is changed to the second background with arrow pointing right. If I click on it again, the background is changed to the original background with arrow facing down.

It’s probably simple, but I’ve been trying for hours and am royally stuck :puzzled: