detect an input corresponding to {TAIL ~ a users selection} of one of the plurality of {HEAD ~ entries}; and 
detect an input corresponding to { TAIL ~ a users selection } of one of the plurality of { HEAD ~ entries } ; and
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH