Agree w/Tom. Do a diagnostic.
What it will show is that you are low on refrigerant.
The refrigerant is the carrier for the oil.
The compressor needs to stay lubed. Hence, low gas= low or no oil to compressor = burnt compressor.
Do not run it til it's recharged. That charge will carry oil to the comp. Good news is, you can get some gauges and a can of r134 at any autozone and save 100-300 dollars by recharging it yourself. Only add to the low pressure side, or the larger diameter line. The one thats cold. The smaller line is high pressure, and the can may EXPLODE if you attempt to charge that line. AVOID THE HIGH PRESSURE LINE.
Look for the port up high on the passenger side firewall on the fat line. Put a gauge on it first to see current pressure with ac on. My guess is it is near 0. Charge until you're at about 25-35 pounds pressure.
Do it slowly, as dumping it in as a liquid will 'slug' the compressor. Should take about 5 minutes per can.
You will need to address the leak.
Chances are the leak is in the evaporator, which is under the passenger side dashboard. You do NOT want to pay to have someone pull apart the dash to get at it. What you want to do is google pro-seal, by Cliplight. Before you add the sealant, you MUST dry the system of moisture or it will not work.
Google Cryo-Chem DRY_PACK.
This post is by george goble who is a facinating guy.
http://yarchive.net/ac/cryo-silane.html
Invented autofrost and got it approved by the EPA, (no small feat) and then patented. With Perdue Univ. I believe. The problem is anything they sell must be bought by an EPA certified tech. Tell your tech to go there and buy a can of the chemdry stuff, add it, then add the sealant, and you should be all fixed up.
Oh, and replace all O-rings.