multiple monitors

I just got a laptop and was playing the S-video out port on my tv with it. Anything on the TV looks really fuzzy compared to the LCD screen, does that indicate a bad cable? or is that just normal. Also, I'm able to use the TV as an extension of my desktop. Is there anyway I can make it just show exactly the same thing that's on the laptop screen? It did this the first time I hooked it up, then I clicked Extend my desktop onto this monitor to see what it did, and when I unchecked it again the TV went black. I want to watch DVD's from my laptop drive on the tv, and the only way I've figured out how to do it is to switch so the tv is the primary and the LCD is the extension, and that's just a pain.