OKLAHOMA CITY (AP) — The father of a central Oklahoma high school valedictorian said Monday his daughter's diploma has been withheld because she used a curse word during her graduation speech.

The Prague High School superintendent said in a statement Monday that Kaitlin Nootbaar "used language that was inappropriate for a graduation exercise." Prague is about 60 miles east of Oklahoma City.

David Nootbaar said his daughter said during her May speech that she had wanted to be a nurse, then a veterinarian, but when people ask what she wants to be now, she said "How the hell should I know? I've changed my mind so many times."

He said Kaitlin's speech was inspired by an installment of the "Twilight" movie series, in which a character used a similar phrase during a graduation scene. He said the written version of her speech used the word "heck," but that she inadvertently used the curse word.

School Superintendent Rick Martin issued a statement in which he called Kaitlin "an outstanding student" whose written speech had been approved.

"Unfortunately, she did not present the speech as written and used language that was inappropriate for a graduation exercise," Martin said.

Nootbaar said he and his daughter went to the school Friday to get her diploma and were met by Principal David Smith

"He said 'Shut the door.' I shut the door and he pointed at her and said, 'You and me have a problem,' " Nootbaar said.

Nootbaar said the diploma was on the principal's desk.

"He said right here's your diploma and you're not going to get it," and then told her she would have to write a letter of apology, Nootbar said.

Martin said he thinks the principal's request for an apology is "reasonable."

Kaitlin Nootbaar has no plans to apologize, her father said.

"She said 'Dad, if I write them a letter it's not going to be a nice letter. It's not going to be an apology,' " Nootbaar said.

Martin said he has had no communication with the family and hopes they'll "contact me personally so that this matter may be resolved between the proper parties."

Nootbaar said he has tried, to no avail, to contact the superintendent.

Kaitlin Nootbaar is attending Southwestern Oklahoma State University in Weatherford on a full scholarship, her father said, and is majoring in biology with plans to become a marine biologist.

He said the university previously accepted his daughter's high school transcript and 4.0 GPA as proof of her graduation.

"She didn't cuss anybody," David Nootbaar said, "and the funny thing is, the school she graduated from, its mascot is a devil."

The school's website identifies the mascot as the Red Devils and shows a cartoonish devil with horns and a pointed tail, winking and holding a trident.