Plasma or LCD?

[ZenGum]

So, I've bought a large HD LCD TV. (Next I will buy a vowel).

I thought I would take a photo to show you all, and I thought it would be cool to connect it to my laptop computer and get the cellar on the screen, and photograph that.

So, cue 15 pin VGA cable, plug, plug ... no success. I can't get the TV to receive any signal from the PC.

The cable goes from the "video out" socket on the PC (dell inspiron running windows XP) to the "PC video in" socket on the back of the TV (Samsung). Using the "source" button on the TV remote, I selected "PC", and "scan for signal" ... and it said "no signal found".

My current guess is that either the PC is not actually sending a signal out through that socket, or it is sending a signal that the TV cannot recognise.
I've fooled around with the Control Panel in Windows, but with no luck.

Do any of you tech-savvy types have any suggestions?