<script> tag issue - double submission of form in FF

<script> tag issue - double submission of form in FF

Yesterday, I ran into a strange issue regarding script tag in a JSP.
Here is the issue

I had multiple script tags connecting to external source js files in the JSP and one of which is empty source

like

<script type="text/javascript" src="file.js"></script>
<script type="text/javascript" src="file1.js"></script>
<script type="text/javascript" src="file2.js"></script>
<script type="text/javascript" src="file3.js"></script>
<script type="text/javascript" src=" "></script>
<script type="text/javascript" src="file4.js"></script>

Because of this empty src script tag, whenever the that JSP is submitted, it submits two times in FF, one with post request and other with get request.  I didnt quite get it why it is submitted twice. Any experts please advise.

Thanks,
RK