Get an S-video cable to connect between your TV back input and your computer S-video output.
Get an audio cable with stereo mini plug on one end for the computer analog stereo audio output and red/white RCA plugs at the other end for the TV audio input.
Be aware that S-video does not give as good a picture as VGA so the computer picture on your TV won't look as good as it does on your computer monitor. (Composite video is not as good as S-video for this purpose.)
It is possible that the TV won't work unless the computer is set to regular VGA (640x480) as opposed to super VGA or 1024x768. You'll have to try it out.
Video hints:
Video Technicalia Made Easy