The method 4, wherein the operation corresponding to {HEAD ~ the selected hard key} is further determined according to {TAIL ~ the displayed screen image} 
The method 4 , wherein the operation corresponding to { HEAD ~ the selected hard key } is further determined according to { TAIL ~ the displayed screen image }
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL