Operator control device in a vehicle, having - a mobile operator control device which comprises a display surface on which at least one display element (19 - 4), to which multiple functions are assigned, can be displayed, - a holder by which the mobile operator control device can be accommodated, - an input device (6, 8, 10, 20) for making an input which is assigned to a function associated with the display element (19 - 4), and - a control device for generating a control instruction as a function of an input into the input device (6, 8, 10, 20), - wherein the holder is embodied in such a way that the mobile operator control device can be positioned in at least two positions, characterized in that - the operator control device has a position-sensing device which is coupled to the control device and by means of which the positions of the mobile operator control device which is accommodated by the holder can be sensed, - the functions which are assigned to the display element (19 - 4) are divided into at least two function groups, - the control device is embodied in such a way that only control instructions of the first function group can be generated if it has been sensed by the position-sensing device that the mobile operator control device is in a first position, and that only control instructions of the second function group can be generated if it has been sensed by the position-sensing device that the mobile operator control device is in the second position, and - the holder comprises a bar and an accommodating device for releasably accommodating the mobile operator control device, wherein the accommodating device can be slid along the bar, and sections of the bar are assigned to the first and second positions of the mobile operator control device. - a mobile operator control device which comprises a display surface on which at least one display element (19 - 4), to which multiple functions are assigned, can be displayed, - a holder by which the mobile operator control device can be accommodated, - an input device (6, 8, 10, 20) for making an input which is assigned to a function associated with the display element (19 - 4), and - a control device for generating a control instruction as a function of an input into the input device (6, 8, 10, 20), - wherein the holder is embodied in such a way that the mobile operator control device can be positioned in at least two positions, - the operator control device has a position-sensing device which is coupled to the control device and by means of which the positions of the mobile operator control device which is accommodated by the holder can be sensed, - the functions which are assigned to the display element (19 - 4) are divided into at least two function groups, - the control device is embodied in such a way that only control instructions of the first function group can be generated if it has been sensed by the position-sensing device that the mobile operator control device is in a first position, and that only control instructions of the second function group can be generated if it has been sensed by the position-sensing device that the mobile operator control device is in the second position, and - the holder comprises a bar and an accommodating device for releasably accommodating the mobile operator control device, wherein the accommodating device can be slid along the bar, and sections of the bar are assigned to the first and second positions of the mobile operator control device.