If you're a VIP going to the U.S. Open, forget about betting on the tennis -- you won't even get in the front door.

We're told the high rollers in Flushing Meadow are now required to sign a document promising they won't gamble on tennis or have anything to do with gambling on tennis....and no signature, no VIP pass. It applies to all players, umpires, big-time VIPs, and credential holders.

The USTA put this in place because of betting scandals at the French Open last year. This is anything but a game for the US Open -- we're told they even hired a security firm run by former NYPD Police Commissioner Howard Safir to "monitor" any gambling activity.