Re: (0,0) point in center?
Okay. 0 is the centre of the picturebox vertically and 0 is the centre of the box horizontally. Why don't you get the user to enter negative values for coordinates nearer the top than the centre and positive values for those values nearer to the bottom than the centre and so on. Now, you know that the centre vertical measurement (cvm) is picture1.height \2. Therefore if the user wants to place a coordinate at -25 then your draw command would take place at cvm - 25.
Does that make sense?
Regards,