Calling a c# method at the end of a flash video

Hi,

   I am currently building a application in silverlight 3 where i do a search for a you tube video and it returns me with a set of videos. I then play the video by embedding the flash player with a HTML-Placeholder in silverlight 3. 

Problem:
I want to determine the end of the flash file and call a c# function (which will play the next video). I don’t know how to archive this.

Any Help with this is greatly appreciated.

Regards,
Pawan