Writing a Hover / Tooltip plugin

Hello,
I'm writing a plugin which only purpose is to add the following code around a selected text in the editor.

<a href="#" onmouseover="setDivVisibility(1);setDivContents('Informative text.');" onmouseout="setDivVisibility(0);"> tooltip / hover text </a>

I'v gotten as far as creating the basis for a plugin. Opening a new window, sending text to it and putting that same text back into the editor.

My questions are:
1. I can not get the raw HTML text sent to my popup. I select text in the editor and click my plug in icon. My new window appears and the text which I selected in the editor is set in the textarea of my new window... but alas, without any HTML formatting tags.

I have combed the forums dry for any idea about what I am missing... but found nothing that helps the issue. One example is this topic, which at first looked like a life saver but later turned out to do nothing more than I had done previously.

2. I have tried searching the forums for more info on how FCK works with selections but so far I have not found much that helped me. What I would like to do is to distill the functionality of fck_link.js. Essentially keep the same functionality of being able to place the cursor (or selection) on a link, press the toolbar button and then enable the user to only enter some random informative text. Once the info/tooltip/hover text has been entered by the user and he/she clicks the Ok button my plugin would add the above described code but with

 setDivContents('Informative text.') 

being called with the recently entered text.

Any ideas / suggestions / comments / whatever would be awesome.

Thank you.

/techo