Getting The URL Of A Page Inside A Frame

[URL] I have an index.html that sets up 3 Frames. They are called FrameTop, FrameA and FrameB. See pic below. In FrameTop the user can type in a url into a textbox with id="urlINPUT". When user clicks LOADA it loads that url into FrameA. User can then browse web in FrameA, clicking links etc and going to new pages. The second button LOADB is designed to determine the current location/url of the page displayed in FrameA and load that into FrameB. So far when I write the javascript in FrameTop LOADA works but LOADB loads the FrameTop into FrameB! [error!]

I suspect my error lies in use of parent/self in the parent.frame.location.

Here is my page layout. [URL]

-----------------Index.html-------------------------------------
<frameset rows="5%,*">
<frame name="FrameTop" src="frame_top.html" />
<frameset cols="50%,50%">

[Code]....

index.html loads the index correctly and displays FrameTop, FrameA and FrameB. The load A button also works correctly BUT when I click LoadB it loads FrameTop into FrameB! This happens when no page is loaded into FrameA AND when an external page in loaded in. [URL]