way 2,
you know tow rectangles can intersect each other if and only if there is two borderlines thath intersect each other so you should check 4*4=16 times it that means you should check every borderline in rectangle one with all the borderlines in rectangle 2 for intersections,I think you can write a simple function that take two lines and determine if they intersect each other then use this function 16 times in your program for implementing this I told you.
Hth.

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Mehdi.:)