REDWOOD CITY, Calif. -- A judge postponed until later this month a preliminary hearing for a 34-year-old Petaluma high school teacher accused of setting up an illicit date with a person he believed was a 15-year-old girl.

Scott Eugene Dietlin, a world history and economics teacher at Casa Grande High School, is charged with three felony counts of sexually explicit communication with a minor, one count of attempted communication with a minor, and two counts of arranging to meet with a minor, Chief Deputy District Attorney Steve Wagstaffe said.

Dietlin pleaded not guilty to the charges Dec. 23.

He was arrested in San Mateo on Nov. 22 after allegedly showing up for a date with "Jackie," a teenage persona created on MySpace by two teen boys, according to Wagstaffe.

The 15-year-old San Mateo County boys posted the online profile as a joke, Wagstaffe said. When Dietlin allegedly contacted "Jackie" in April, the boys initially played along, he said.

Over time, the communication included sexually explicit e-mails and text messages, police said. At one point, Dietlin allegedly sent "Jackie" a naked photo of himself, Wagstaffe said.

The boys finally decided to call police, Wagstaffe said.

Burlingame officers began posing as "Jackie" and set up a date at a location in San Mateo on Nov. 22, Wagstaffe said.

Dietlin showed up that morning and was taken into custody, police said.

Burlingame police searched Dietlin's car and Petaluma home, seizing items including condoms, a computer and a cell phone, police said.

His preliminary hearing, originally scheduled for Thursday, was reset to Feb. 19, according to Wagstaffe.

Dietlin remains in custody in lieu of $700,000 bail.