You can only do it if the TV is expecting to get signals from a laptop. Our TV has a special socket for the laptop/PC which is exactly the same as the kind on a computer monitor, so you can just join it up.
I think if your TV doesn't have something like that, then you can't directly connect them up. I don't know if there's any kind of widget you can use to convert from a PC output to a TV input.
it depends on your laptop. My laptop has an S-video output (small round one with 4 holes on the side), so used an 's-video and twin phono to scart converter'(see maplins) then you need 2 headphone jacks (you know the things you use on your headphones so the socket fits in the little hole) to put on the phono sockets which then go in the headphone socket of the laptop. OFC all that said you could just take your laptop into Maplins and ask for the bits you need.