Updated

Two Neuqua Valley High School students won't be able to wear T-shirts saying "Be Happy, Not Gay," to school on Thursday following a judge's ruling.

U.S. District Judge William T. Hart ruled in favor of the high school Tuesday in a preliminary injunction that would have allowed the students to wear the shirts the day after Wednesday's National Day of Silence.

On the Day of Silence, students can refrain from speaking as an effort to protest discrimination against homosexuals.

The Arizona-based Alliance Defense Fund is representing Heidi Zamecnik of Naperville and Alexander Nuxoll of Bolingbrook in a lawsuit that claims Zamecnik's rights were violated last year when she wasn't allowed to wear the shirt in school.

The Alliance Defense Fund, a conservative Christian litigation group, will appeal the judge's decision on the preliminary injunction to the 7th Circuit Court of Appeals, attorney Jonathan Scruggs said. The lawsuit is still pending.

Scruggs said the school is violating the students' rights to free speech by banning the shirt.

"The school cannot silence speech merely because some people find it offensive," Scruggs said. "We believe that's the core of what the First Amendment protects."

Jack Canna, an attorney for Indian Prairie Unit School District 204, said banning the shirt is part of a policy "to preserve the notion that kids shouldn't make negative or derogatory comments about other students."

Messages left by The Associated Press with the Indian Prairie Unit School District 204 and Neuqua Valley High School were not immediately returned Wednesday morning.