cant get video to show on tv through laptop

hey lads. i have .avi/xvid etc movie files that i would like to play on the tv cos its a bigger screen u know. so i connect the laptop through the s-video cable and i can see my computer screen on the tv - great! until i play the files then the section of the tv where the video file should be is blank. If any of ye know what im talking about and can help please do. im going crazy here!

Read this:http://www.svideo.com/compaq1700.html

thanks alot man couldn’t have done it without ye.