Image Changes On Text Hover?

I have 7 links that need an image to change on hover. I can get it to work for the first, but not for the rest. The code I'm using is:

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<script language="JavaScript">
<!-- Hide the script from old browsers --
img0_on = new Image(50,50);
img0_on.src="change.gif";
img0_off = new Image(50,50);
img0_off.src="load.gif";
function over_image(parm_name)
{
document[parm_name].src = eval(parm_name + "_on.src");
}
function off_image(parm_name)
{
document[parm_name].src = eval(parm_name + "_off.src");
}
// End Hiding Here -->
</script>

Then: <IMG SRC="load.gif" name="img0">
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However, I've tried adding img1 etc etc with different src but disables the whole function.