How do I connect my laptop to my my flat screen tv?

I have a laptop and want to connect it to my flat screen tv. My laptop has the socket out, my tv has the socket in, and I have the lead to do it... is it hdmi lead or something. I just haven't got a clue what I need to do. Neither my pc manual, or my tv manual give me the necessary information, so please help would be greatly appreciated. Thanks in anticipation. Roy Barber