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.

>>12

well I was just fucking around

cos(theta) = magnitude Y-component of a normalized vector.

I was just fucking around but you get the picture its not too hard you fuck