With so few elements it is hard to tell.
What does the JS URL look like ?
If you use backslashes like “path\to\my\js” it will work in IE and Chrome as they are more tolerant but fail in firefox, using forward slashes like “path/to/my/js” should work everywhere as it is the standard.
If it is not the problem, please post the URL you are using and your web.xml content so we can hopefully find the cause.