Selecting a Bezier

Hi,
I have a program that involves drawing a set of beziers from one point to another. Now my problem is i have to add the functionality of selecting the bezier by clicking on top of it.I came to know that there is a formula by which i can find the bezier thats present at the point where i click.I am not able to find the formula or a way to select a bezier when i click on it.

thanx in advance
Muthu

What method are you using for drawing the curves in the first place?

DrawBezier(pen,point,point,point,point).

Muthu