How would you make this news ticker?

I basically want to make a news ticker/flasher that if the user move the mouse over, the news ticker will expand upwards to show a brief description of a particular topic. The data will be passed to flash via XML.

I made an image of this process.

I followed some XML tutorial here and I finished with the “news flashing every 5 sec” part. I just dont know how to stop at a particular title and start where it left off after a user move the mouse away.