I need help creating a javascript that will change the source for an image using the following


Code:
<img id="wrench" src="spanners.jpg"
alt=".." width=".." height= ".." />


document.getElementById("wrench").src=
"monkey_wrench.jpg";

The java script would run when i click a button that is tied to a specific picture and display that photo by change the source information.

However I have tried a couple things but nothing seems to work... Can someone at least point me in the right direction.