Calculate where lines intersect

hey,
I have been playing around with the fmx2004 drawing api. I am drawing a complex shape and all is well but I would like to make the lines smoother. I haven’t been able to find a smoothing function but I am working on a custom solution using the curveTo method.

I have to be able to calculate where two lines intersect. i have their slopes and two points along each line, so now all I need to do is calculate their intersection. I can do it on paper but not in flash, can anyone help me?

thanks