I am developing a site and everything (including javascript) works perfect in Firefox 32.0 and Chromium 28.0. I have not tested in IE coz am on an Ubuntu 13.04 machine. I tested in Opera 12.16 and suddenly my javascript doesn't work.

Javascript is checked in opera preferences and all my external jquery and javascript scripts have the type="text/javascript" part. Still no good. I have commented out all my external script files including jquery and then added a <script type="text/javascript"> alert('JS working'); </script> in the head. Still no good. Alert working in Firefox and Chrome but not in Opera.