B737 CREW RETURN LAND AFTER DETECTING SMOKE IN COCKPIT IN RSW AIRSPACE.

Narrative

AFTER TKOF; DURING CLBOUT; APPROX 3000 FT; WE NOTICED A STRONG SMELL OF SOMETHING BURNING IN THE COCKPIT. AS WE DISCUSSED THIS; WE RECEIVED SEVERAL CHIMES FROM THE FLT ATTENDANT CALL. THE FO TALKED TO THE 'A' FLT ATTENDANT WHO SAID THAT THERE WAS SMOKE IN THE CABIN. I (CAPT FLYING) TOLD THE FO TO DECLARE AN EMER AND TO GET BACK TO THE ARPT IMMEDIATELY. WE WERE APPROX 10 MI OUT; AND I LEVELED OFF AT 6000 FT. AFTER RECEIVING VECTORS TO RETURN; I ACCELERATED TO APPROX 290 KTS WITH SPD BRAKES OUT DURING THE TURN TO GET BACK DOWN RAPIDLY AND REQUESTED RWY 6 (WITH ILS) TO LAND. WE HAD JUST DEPARTED RWY 24. WE PROCEEDED WITH ALL APCH AND LNDG CHKLISTS; REQUESTED EMER EQUIP AND LANDED UNEVENTFULLY. I STOPPED IN FRONT OF THE EMER TRUCKS AT THE HIGH SPD EXIT AND TALKED TO THEM. THERE WAS NO OUTSIDE FIRES. THE FLT ATTENDANT RPTED TO US THAT THERE WAS NO SMOKE IN THE CABIN ANY MORE. I OPTED TO TAXI TO THE GATE AND GET THE PAX OFF THE AIRPLANE. THE FIRE/RESCUE THEN PROCEEDED TO CHK THE ACFT INSIDE AND OUT TO CHK FOR FIRE OR SMOKE. NOTHING WAS FOUND EXCEPT THAT THE SMELL CAME BACK ON THE GND AGAIN INSIDE THE ACFT. AFTER TALKING TO THE CHIEF PLT; I REMOVED MYSELF AND THE COPLT FROM THE FLT; AS WE WERE VERY NERVOUS AND STRESSED OUT; AND FELT WE COULD NOT FLY ANY OTHER ACFT THAT NIGHT (FOR SAFETY REASONS) AND STATE OF MIND. SUBSEQUENTLY MAINT STARTED CHKING THE ACFT; BUT I HAVE NO KNOWLEDGE OF WHAT THEY FOUND.