Jason Alexander, who was married to Britney Spears for a total of 55 hours has been sentenced to 10 days in jail for violating the terms of his 2006 DUI arrest.

"Jason messed up and he knows it," an insider tells Star. "He's going to keep his head down, stay out of trouble and hopefully he won't have to serve the entire 10 days."

Alexander was sentenced to a court ordered alcohol rehab and educational program that required two visits to the county morgue. A sort of scared straight, you drink, you drive, you end up here kind of thing but instead of following the judges orders, he skipped both appointments.

He is currently behind bars in the LA County's Twin Towers complex, where Paris Hilton did her part of her stint, and is scheduled for release on December 9th barring an early release for good behavior.

After a long night of partying Britney and Jason were married on January 3, 2004 during an early morning ceremony at Las Vegas' Little White Wedding Chapel. A judge granted an annulment on January 5th, after 55 hours of wedded bliss.