This should be in the drug testing section.
[Mod Note: Thread moved to the drug testing forum]

Not many options. Either come up with some clean urine from someone you absolutely KNOW is clean or pickup up some synthetic urine like Quickfix. Usually any smoke shop will have some. I buy Quickfix for $18 at my local smoke shop. Be sure and practice. If you buy quickfix you can reheat many times to practice. If you get clean urine, use water to practice with.