An apparatus and method for using a scroll sensor providing a touch sensitive control input surface for a plurality of control functions is provided. The input surface is divided into a plurality of regions. Each region is assigned to one of the plurality of control functions. At least one of these control functions accepts parametric control input. A first touch is received at one of the regions on the input surface. The control function assigned to the touched region is selected. If the selected control function is one of the control functions accepting parametric control input, a second touch on the input surface is received as parametric control input during an activation period for the selected control function. The second touch may be received as parametric control input at any point of the input surface.