Hyundai Repair: Hyundai accent a/c repair, accent crdi, paint expert

Question
I am having  a accent CRDi 2003 model. It has already completed 76000kms. My a/c during summer works on and off only - soon after switching works for 15-20min. then stops [even the air is as hot as outside air] Then after 5-10min. it starts working. This cycle contiues, but the time in whch the a/c works becomes less and less gradually eachtime. Can you help me about the problem.
            Thank you

Answer
Hi Sivian,
I am not a mechanic. I signed up on this website as an AUTO PAINT expert and somehow this website is sending me mechanical questions.  Go figure.  Is there a shortage of Hyundai mechanics?  Probably so. In which case, if i were in your shoes, and wanted to pay only ONE time to get it repaired correctly with a GUARANTEED repair -  i would go to a Hyundai Dealership with authorized AC repairman on premises.

I have a Hyundai factory sticker under the hood of my Tiburon that says something like "DANGER-only Hyundai factory trained A/C repairmen have ability to work on this AC".  i do not know the consequences of letting Jim Carey, Jerry Lewis or the Three Stooges work on Hyundai AC units but i bet it is more than any of us wants to pay.
Sincerely, Your friendly auto paint expert.