PIC OF AN A320 FAILS TO PROGRAM HIS FMS PROPERLY AND THE ACFT BYPASSES THE 'CLRED DIRECT TO' WAYPOINT. ZLA CTLR QUESTIONS ROUTING.

Narrative

ON THE OFFSHORE 3 DEP OUT OF SFO AROUND CYPRS INTXN; ATC CLRED US DIRECT LAX. THE AUTOFLT SYS WAS ENGAGED AND I SELECTED DIRECT ON THE MCDU AND LINE SELECTED 'LAX.' THE ACFT TURNED TO AN APPROPRIATE HDG AND WE CONFIRMED. ABEAM LAX; CTR ASKED IF WE WERE DIRECT JLI; AND I LOOKED AT THE MCDU AND THE NAV DISPLAY AND SAW THAT WE WERE INDEED GOING DIRECT TO JLI. WE WERE SHOWING 12 DME FROM LAX. (JLI WAS OUR NEXT WAYPOINT AFTER LAX.) I DO NOT KNOW HOW JLI GOT TO BE THE 'TO' WAYPOINT BUT I HAVE 3 POSSIBILITIES: 1) I SELECTED JLI RATHER THAN LAX; 2) WE PASSED OVER A WAYPOINT WHEN I PUSHED THE LINE SELECT FOR LAX; THE WAYPOINT SCROLLED; AND JLI WAS SELECTED; OR 3) WE CROSSED OUR LAX WAYPOINT AS ATC ASKED; SO JLI WOULD BE THE NEXT WAYPOINT. I THINK SCENARIO #2 TO BE THE MOST LIKELY. TO PREVENT THIS; I RECOMMEND THE PROC TO BE: 1) PRESS DIRECT; 2) TYPE THE IDENT IN THE SCRATCH PAD; AND 3)LS 1L; THE (DIRECT TO) PROMPT. OBVIOUSLY I SHOULD HAVE XCHKED THE MCDU ALSO TO CONFIRM THE CORRECT WAYPOINT WAS ACTIVE.