2000 Sentra SE Air Cond. stopped blowing cold air

2000 Sentra SE
2.0 engine
89,000 miles
No funny sounds, no unusual smells.
No leaks

5 months ago had the 90,000 service


Last week the AC worked great. Did not use the AC for 5 days. Now it does not work at all.

Belt is Good.
Fuse is good.
blower/fan works
light on ac switch comes on

I CANNOT figure this one out :o