Abstract: A moveable, rollaway door or window panel is provided in a structure having one moveable panel and one fixed panel. The moveable panel, when in its closed position, is substantially co-planar with the fixed panel; and when in its fully open position, it is substantially co-extensive with and on the interior side of the fixed panel. A pair of control rods, one at each side, is concealed within the sash structure of the moveable panel, and is secured at its top and bottom ends to a cam member. Each cam member has a guide member which co-operates with a guide track, and is rotatable with respect thereto. The cam members at the upper ends of the control rod are connected to each other by a tie rod or cable in such a way that rotation of one of the control rods causes an equal rotation in the same direction of rotation of the other of the control rods, thereby assuring planar movement of all four corners of the moveable panel.