AceShowbiz - Executives in charge of Britney Spears' latest music video made sure it was free of all temptation, by ordering staff to ensure the star was not exposed to alcohol or drugs. All performers working with the singer on her latest "%sTill The World Ends%" clip were required to sign a six-page agreement banning them from exposing sober Spears to drink or drugs.

The document, obtained by TMZ.com, reads, "Contractor acknowledges that it is essential that (Britney) not be exposed to any alcohol, drugs, or controlled substances." The contract also states that dancers can be subjected to urine testing at any time and dismissed for failing a test or even refusing to take one.

Spears began cleaning up her act in 2009 in a bid to ensure she maintains her shared custody of her two sons with ex-husband Kevin Federline.