Hi Al, thanks for the help. Quick question (see below in bold).

>>Does anyone have a function that can determine the intersection of 2 lines? I know the start and end points of each line in coordinates (they are 2 element arrays of doubles).
>>
>>tia
>
>I'll give it a shot. I won't use subscripts, so case is important below:

>Suppose line 1 runs from X1,Y1 to X2,Y2 and can be described by the formula
>
>Y = MX + B, then

<b>What is MX? M * one of the X cords?</b>

>
>M = (Y2 - Y1) / (X2 - X1), and
>B = Y1 - MX1

<b> MX1 is M * X1, correct?</b>

>
>Similarly, if line 2 runs from x1,y1 to x2,y2 and can be described by the formula
>
>y = mx + b, then
>
>m = (y2 - y1) / (x2 - x1), and
>b = y1 - mx1
>
>At the point of intersection, y = Y, so
>
>MX + B = mx + b
>
>Also, at the point of intersection x = X, so
>
>MX + B = mX + b
>
>MX - mX = b - B
>
>X(M - m) = b - B
>
>X = (b - B) / (M - m)
>
>Once you have the value of X, you can get the value of Y from the first equation.

Good luck!