1998 Jeep Laredo

Air Conditioning problem
1998 Jeep Laredo 6 cyl Four Wheel Drive Automatic 233000 miles

It appears that the A/C condensation somehow leaks onto the passenger floorboard, keeping it damp most of the time. When I don't use the A/C it doesn't happen. I can't tell where it's coming from. Someone suggested a clogged drain tube, but I don't know where to look for it or how to unclog it. Any suggestions?
August 29, 2010.

Look on the firewall in the center, follow it down until you see a rubber elbow tube facing downward, gently put a skinny coffee stirer or something like it and move it in and out unclogging the drain tube.

Aug 29, 2010.