keeps draining battery

please advise i have put a new battery on a couple of days ago and just went to start it and its dead again
i have no idea what to do know

I had a drain once, fitted one of these as a short term measure till I went through the electrics to find the drain

http://www.frost.co.uk/battery-cut-out-switch.html

useful as a bit of additional security too

Unplug the alternator and see if the drain stops - faulty diodes can flatten your battery, it's an easyish fix. Otherwise it's chasing the drain through the wiring with a multimeter.

Check the voltage on the battery with everything off and a fully charged battery should be nearly zero. If its high pop fuses out one at a time and check if it drops if it does follow that fuse thats your problem. If no joy not everthings fused so you may have to disconnect some lights/ accesories from the scource to check if its them. If still no joy as above its probs your alternator. Or could be a bad earth try a jump lead off the - terminal to chassis then check volts again