I am using a JavaScript page that acts as a 'side-by-side' tester. It sends the same form in a POST to two different servers. One server is usually the production server the other a server under test.

The results returned by the servers are displayed in two frames aligned side by side on the page.

This page has worked in Firefox for several years. It worked up till early last week. Now, instead of populating the two frames, a new window opens up to display the response received from the Server.

Nothing has changed in the code so I'm thinking that possibly the latest release of Firefox (10.0.2) has somehow broken this page.

Here is the code that is envolved:
Code:
// setting up the frames
<frameset rows="400,*">
	<frame src="file:///C:/TestSanity/controller.htm" name="controller"/>
	<frameset cols="50%,50%">
		<frame src="leftFrameInitialContent.html"   name="leftWindow"  onload='parent.controller.stopLeftFrameClock() ;'/>
		<frame src="rightFrameInitialContent.html"  name="rightWindow" onload='parent.controller.stopRightFrameClock();'/>
	</frameset>
</frameset>

// sending a request whose response will be displayed in a frame
// pick the form that matches the current command
	formToSubmit = document.getElementById(command + "_FORM") ;

	// set the left frame destination url (action) from the value on the UI
	formToSubmit.setAttribute("action", document.getElementById('leftFrameBaseUrl').value );

	// send left window request
	formToSubmit.setAttribute("target", "leftWindow");
	formToSubmit.submit();
I don't have any idea what to look for as a cause. Any help and/or suggestions would be appreciated.

Thanks,
bkey