Corresponding points in different viewports.

Hi everybody, I have a problem that deals with corresponding points in diffrent viewports. Here is my setup, I have the main viewport that defines the window, main_viewport, then I have two views that are defined by right_view and left_view (they’re viewports). I want to select a point on the left_view and display it in the right_view. I select a point by clicking on it and then I get world coordinates of that point, then I try to project it in the right_view but it doesn’t quite work: it doesn’t show the correspoding point. What should be the proper way of doing it? thanks,