is it going to be a monitored give or not? if its not, you can just go online and buy a product by a company called urine luck, and get their synthetic urine.. if its monitored, you can go and by one of those whizzinator things and use the synthetic urine with that..
i have to take ua's about once a month or so, and not for a job or probation or the courts or anything, and they started busting my balls for being dirty for thc.. i finally bite the bullet and went and got a whizzinator, and haven't looked back yet.. those things rock, and i've passed every ua since than..
the first couple of times i had to use it, i was super nervous as i'm monitored and i thought that the person surely had to see my big fake penis, but he never had a clue and it works like a charm..
i also know that alot of people say that they have luck with niacin, but i've used other flushing products in the past and still came up dirty..
just one last thought.. i would always go to the drug store and get one of the home testing kits like a day or so before you have to take the ua that counts, and do everything that your going to do for your ua, and see if you come up clean or not first at home before you have to give the real one.. this way you will know ahead of time whether or not you will have passesd and you won't have to be stressed out untill you get the results..