Algorithm for orientation of a 2d vector?

Hey; I was wondering if there is a simple algorithm that takes an x and y value (the values of the vector), and returns the angle between north and the vector, clockwise? All that I learned in trig class back in school has left me, and Google isn't giving me anything useful.

>>4
Aha! I knew there had to be a function like that. Thanks!

>>5
Because I'm not so great with trig.