image swapping in forms?

I am trying to perform an image swap in a form using the input type of 'image'. For some reason, onmouseover or onmouseout does not work when I assign it different images:

<form onsubmit="window.open('weblink.html')">
<input name="image1' type=image src="image.jpg" border=0 onclick="submit()"
onmouseover="document.image1.src="imagealt.jpg"
onmouseout="document.image1.src="image.jpg">
</form>
I have tried using onmouseout/onmouseover in various combinations to achieve the effect and it only seems to work OUTSIDE of the form tags.
Can anyone offer any useful advice?

a couple of things:

make sure you keep your single and double quotations straight.

if you embed javascript, call it first by saing javascript: and then the stuff you want.

<form onsubmit="window.open('weblink.html')">
<input name="image1" type="image" src="image.jpg" border=0 onclick="submit()"
onmouseover="javascript:document.image1.src='imagealt.jpg';return true;"
onmouseout="document.image1.src='image.jpg';
return true;">
</form>

see if that works, otherwise move the rollover to a function and call that function.

-b