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