turbo troubles!! please help

Hi, ive got a golf mk4 1.9tdi 90php, done 50,506miles X reg (2000)

turbo seems to be fine when the engine is cold but when engine gets warm the turbo starts to stutter. and sometimes the turbo cuts out completely.
the other day i had to turn the engine off then start it again and the turbo would be working but not properly, still stutter!

CAN ANYONE HELP ME?

What you're describing could really be any number of things. I suggest the first thing you do is get the fault codes read using a diagnostics machine or VAG-COM, at least then we'll know what the exact problem is and can try to point you in the right direction, otherwise it's just complete guess work.