Abstract: A control comprising a main window and control element movable within the main window is used to control a plurality of scaled parameters. The control is implemented in a graphical user interface for a computer system having a memory, a processor, a display and an input device. At initialization, the x,y coordinate of the control element with respect to the main window corresponds to initial values of a first and a second scaled parameter. As the control element is moved within the main window according to a set of input signals from the input device, a second x,y coordinate of the control element is determined. The first scaled parameter is adjusted according to an x value of the second x,y coordinate and the second scaled parameter is adjusted according to a y value of the second x,y coordinate.