are you using a pc? if so then this is how. i do it all the time with my laptop. to use your tv as a monitor you are going to need a s-video cable. and of course make sure your computer has the s-video output. then plug it into your tv, then you have to hold the function key along with the monitor key, which should be f4. if it isnt f4 just try all the f keys. it really depends on the keyboard. if it doesnt come up right away then hold the 2 keys for a few seconds or push both keys at the same time a few times. hope this helps.
Just a word of caution. Don't sit close to the TV screen like you would with a computer monitor, or (over time, but not that long) you'll burn out your eyes' retinas. Of course this is only for CRT TV's. You don't have to worry about this with Plasma or LCD. I’m serious, you can seriously damage your eyes and the damage is irreversible.
