Transmission Failing

What is your question?

I have a Audi TT S Line 2005 when it warms up the transmission starts failing, it will go like in nutral and than jumps back in gear. it happens between the 1st and the 2nd and 2nd the 3rd gear and also in reverse, and when it downshift it will jumps into the gears. And when it cools up it will drive perfect till it warms up again. Can somebody please tell me what's wrong with my car?