Hello, I want plot with pst-3dplot the function : z = 2x(y + 1) with 0 < x 10, 0 < y < 12 and 0 < z < 260 In fact, I want the lines : z = 40, z = 80, z = 120, z = 160, z = 200, z = 240. How can I do this. Thanks for your answer. Denis