Hey, you need to make sure the image has an ID:
Code:
<img src="initialImage.jpg" id="theImage" />
Then at the top of the script you should then add the line:
Code:
var theImage = document.getElementById("theImage");
to reference the image.
Then where the document.write code is you should change it to:
Code:
theImage.src="will.jpg";
which will change the source attribute of the image (changing the image).
Cheers,
Jamey