Stop Sleep Mode

[theheard]

I am using linux and running a webserver to test webpages and scripts on, but it always goes into sleep mode. I somehow turned X off so it's all command line environment. Can someone tell me how I could stop it from going into sleep mode?

Thanks

[theheard]

forgot to specify that I am using Knoppix

[CrashedAgain]

Boot with cheatcode noapm. It will also mean that you will have to shut down manually as apm runs the auto power off shut down. I have to do this on my laptop as it will not wake up from sleep mode.