Monitor on/off

I noticed when I run Windows 2000 the monitor is automatically turned off if no key is pressed and the mouse is left idle for about 20 consecutive minutes. The monitor is reactivated upon pressing any key on the keyboard or simply moving the mouse. When I run SuSE 7.3 the monitor is kept permanently on no matteer the elapsed time since the last keyboard entry . I wonder whether it is possible to get SuSE Window Manager behave the ame as Windows does. Thank you in adavance for your help. MEM