ACFT MAKING VISUAL APCH LINED UP ON THE WRONG RWY.

Narrative

ON THE ARR TO LAX WE DEPARTED SANTA MONICA HDG E AND FROM THE COPLT SEAT I OBSERVED ACFT LNDG AT LAX ON RWY 24 AND RWY 25. HOWEVER; THERE WAS A 'FINGER' OF FOG OVER THE NORTHERN RWYS FROM THE THRESHOLD AND W. AS WE TURN BASE AND DSNDED FROM 5000 FT WE WERE CLRED TO 2600 FT; TUNED THE ILS AND OM. LAX APCH ASKED IF WE HAD THE RWY IN SIGHT; I SAID 'NEGATIVE' AND THEY REPLIED 'THEN MAINTAIN 3000 FT.' THE CAPT SAID 'YOU DON'T HAVE IT YET?' AND I LEANED BACK IN MY SEAT SO HE COULD SEE BEYOND ME AND I SAID; 'DO YOU WANT TO CALL IT?' AND HE SAID 'I HAVE IT; CALL IT.' I CALLED 'RWY IN SIGHT' AND WE WERE CLRED FOR THE VISUAL TO RWY 24R. THE CAPT ASKED FOR GEAR; LNDG CHKLIST; AND FLAPS 28 DEGS; PLUS WE HAD A TCASII TA; SO I WAS 'HEADS DOWN' IN THE COCKPIT; PLUS LOOKING OUT L AND BEHIND THE CAPT FOR TFC. AT THIS TIME THE JUMPSEATER AND LAX TWR (N) SAID YOU'RE LINED UP ON THE WRONG RWYS. WE ADJUSTED TO THE R TO ALIGN WITH RWY 24R AND LANDED WITHOUT INCIDENT. FROM SANTA MONICA INBOUND I WAS TALKING ABOUT THE FOG OVER THE N COMPLEX; HOW I SAW ACFT LNDG DISAPPEAR UNDER IT. ALSO; I KNEW THE N COMPLEX WAS GOING TO BE MORE DIFFICULT TO DISCERN. I THOUGHT THE CAPT REALIZED THE DIFFICULTY OF SEEING THE RWY 24R RWY AND THAT'S WHY I WAS RELUCTANT TO CALL IT IN SIGHT. WHEN HE SAID 'CALL IT' I DEFERRED TO HIS EXPERIENCE AND WENT ABOUT MY PNF DUTIES. IN RETROSPECT; I SHOULD HAVE ENSURED FINAL ALIGNMENT WITH THE ILS AND OM TO BACK HIM UP AND COULD HAVE COMMUNICATED THE VISIBILITY DIFFICULTIES MORE CLRLY.