My a/c unit when I turn it on all it does is blow out warm air even when its set at 72 degrees ,so could any one tell me what the problem might be.

There are several possibilities.

One being that you are very low on freon.

Another is that you filter could be very dirty, of the filter has been dirty for so long that the Evapoartor coil has gotten stopped up and will not let enough air through.

Next could be that you outdoor fan is not turning and the compresor overheats and turns it self off.

Or the compressor itself could be bad and will not run or a capacitor is bad and will not start the fan or the compressor.

If you will tell me what the unit is doing maybe I can help you better.