My ac at home is not working. It's just blowing out warm air. There is nothing that I see wrong with the unit outside. The fan works and everything.

If someone knows what I could check to see what's wrong, that would be great.

Thanks

?? What kind of equipment you got? Tell us more,, is it a package unit?is it a split system with a/c outside and furnace?airhandler inside?, if the blower inside is blowing,if the outside fan is running,if the compressor is working,you should be able to feel the larger 3/4 in copper tubing going from unit to the inside and feel if its cold,cool,or nothing,tell us more info