mozilla: script works fine in HEAD, but not in external *.js file

The facts: I call the changeImages function from the body of the HTML document as follows:

<A HREF="#" ONMOUSEOVER="changeImages('freezeranimationmedium_01', 'images/freezeranimationmedium_01.gif'); return true;" ONCLICK="changeImages('freezeranimationmedium_01', 'images/freezeranimationmedium_01-c.gif');">
<IMG NAME="freezeranimationmedium_01" SRC="images/freezeranimationmedium_01.gif" alt="FreezerCrash" STYLE="border: 2px dashed black;"></A>

The changeImages function is this:

function changeImages() {
if (document.images ) {
for (var i=0; i<changeImages.arguments.length; i+=2) {
document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
}
}
}

The changeImages function sits in an external file HD.js which is referenced in the head of the document as follows:

<SCRIPT SRC="HD.js" type="text/javascript"> </SCRIPT>

The problem: Everything works fine in IE. For Mozilla, I get a 'changeImages is not defined' error on the Javascript console. When I stick the changeImages function right into the head (that is, no external *.js file) Mozilla likes it fine.

Surely there is support for external *.js files for Mozilla?! I'm hoping there's some obvious syntax error that IE forgives but Mozilla does not, which somebody can spot ... the page in question is at www.homelessdave.com/index.htm

Thanks in advance.

Cheers, HD

Firefox also shows this error.

Error: missing formal parameter
Source File: http://www.homelessdave.com/HD.js
Line: 57, Column: 28
Source Code:
function cost(box,scientist,protected) {

The word "protected" is a reserved word. Call it something else.
Fix that first. I bet it makes the other problem go away.

FWIW, the image switch did fine in my Firefox and lagged funny with Avant Browser (IE).

NikkiH's diagnosis above was spot on. Thread over.

HD