Good point. We do need a native one -- Birdie rolled this one early in the beta, so I know I've overlooked the need for it since then!
Function OverLap (x0, y0, x1, y1, x2, y2, x3, y3)
If x0 > x3 Or x1 < x2 Then Return False
If y0 > y3 Or y1 < y2 Then Return False
Return True
End Function