Note, this has been asked repeatedly before and should have appeared in a list of questions at the "do you really want to post this question?" section. If not, my apologies.
I had no intention of answering this question in full, prefering to use a link to one of the previously answered threads, but since a cursory search to find one proved fruitless I thought it useful to supply a repeat of the solution.
Ah yes stevie21 you could find the previous answers using Threads I'm involved in or Q's I gave answers to whilst us lesser mortals have to rely on the (not quite adequate) search feature ;�)