screen blanker

Hi i have been trying to set the screen blanker from the default of 10 mins to 60 mins as it saids in the suse docs like setterm -blank 60 and it doesnt seem to work also try like setterm -blank [60] and it doesnt work can someone tell me how to do this or what i need to do where either at an vt or in yast or yast2 thanks in advance Bob