press ups dont have anything to do with pull ups mate, completely different muscles, do negative pullups mate, (jump up to the bar chin over the top overhand etc etc, then lower yourself down slowly about 5-6 seconds, and do 3 sets of 6 of those twice a day, you will be able to do one in no time, then once you can do one, your away, just bang out one every time you go past the pull ups bar, and then once you get two start doing sets, and they will increase prob 1-2 every couple of weeks till then, i couldnt even do 1 about 2-3 months ago, but now i can do 8. it works bud.