Like Burnt Toast said, Quick fix is 100%, as long as the temp is right. I have only used it once, and it was fine. There are many other success stories on here about quick fix, or any other synthetic urine. Read the subbstitution sticky at the top of the forum, then search aroung the drug testing forum and you find the info and reassurance you are looking for.

Good luck, subbing is very easy, and leads to many paranoia free tokes!