HOUSTON (AP) _ Lawyers picked a jury Thursday and began testimony in a case of potty parity.

Denise Wells, a 33-year-old legal secretary, is being tried for using the men's restroom at a concert. Her trip to the toilet made national news and led to talk-show appearances with Johnny Carson, Geraldo Rivera and Joan Rivers.

But on Thursday she was barred by her lawyer and sister, Valorie Wells Davenport, from talking to reporters.

At one point before the proceedings began, she went to the women's restroom and emerged smiling while nearly a dozen photographers clicked away.

She was ticketed for allegedly violating a city ordinance that bars members of one sex from using a public restroom designed for members of the opposite sex in a manner calculated to cause a disturbance.

She faces up to a $200 fine if convicted of the misdemeanor.

Some states, including New York and Virginia, have approved so-called potty parity regulations that give women as many or more toilets than men to compensate for the extra time that women can take.

In 1988, two Virginia Tech researchers with stopwatches and questionnaires found that a woman's visit to a public restroom runs 50 percent longer than a man's.

Ms. Davenport said her client's defense in the trial that was expected to last at least two days would be based on a clause in the law saying the person intended to cause a disturbance.

''She was just trying to go to the bathroom, not cause a disturbance,'' Ms. Davenport said.

Ms. Wells used the men's restroom at The Summit during the July 7 concert by country music star George Strait because the line outside the women's restroom was too long.

Ms. Davenport said her sister waited until intermission ended and again tried to use the women's room, but the line was even longer. Then, in desperation, she followed a couple into the men's room, while the other woman's date cleared the way.

Police officer Daniel Ramsey was working as a security guard at The Summit when he found Ms. Wells using a men's restroom.

Ramsey testified that he saw her coming out of a stall.

''She said in a voice that could be heard to the front of the restroom, 'There - I left the lid up, just like y'all like it,''' he said.

Ramsey said he escorted Ms. Wells out of the bathroom and cited her.

Potential jurors were asked if they'd ever been in a public restroom intended for the opposite sex.

Ten of 30 potential jurors raised their hands. Each explained their reasons, including the same reason offered by Ms. Wells, that there were too many women waiting for their restroom while the men's room had toilets available.

Ms. Wells was surrounded by family and friends who snickered at some of the panel's responses.

''Let's face it. We're everywhere. We've got a woman lawyer, a woman defendant, a woman judge, we may even have a woman governor,'' Ms. Davenport told the panel. The last reference was to the Democratic gubernatorial candidacy of Ann Richards.

During questioning before Municipal Court Judge Francelia Totty, several male jurors said they had been offended by young women who entered men's rooms giggling and used the toilets while men were present. But, they said, ''by the desperation in their manner'' it was clear the women felt it was an emergency situation.

''Even though it's a minimal case, it's still a crime and it's my belief and Denise's belief that she did not violate that ordinance,'' said another lawyer for Wells, Christopher Tritico.

Tritico said Ms. Wells did not enter the men's room to shock anyone.

''I don't think the ordinance in and of itself is wrong, but the way it is drafted, it allows people in an emergency to get relief,'' Tritico said.

''She violated a city ordinance,'' said Karl Rosette, the prosecutor. ''She entered without the permission of the person in charge.''