Dallas ? Chocolates are always nice, and a diamond necklace would be delightful. But a Dallas-based ministry thinks it has a better idea for Valentine’s Day.

“Her gift for Valentines? Stop looking at porn,” proclaim billboards put up by NetAccountability, a nonprofit software company that aims to help Christians confront the “secret sin” of pornography.

If national surveys are any indication, it is a personal battle waged by millions of Christians.

Almost 18 percent of people who called themselves born-again Christians admitted visiting Internet porn sites, according to a 2000 survey of 1,031 adults by the evangelical group Focus on the Family.

In a 2002 Pastors.com survey, more than 50 percent of responding pastors reported viewing pornography in the previous year.

“It’s definitely the church’s dirty little secret,” said Mike Foster, co-founder of the anti-porn site XXXChurch.com, which has online support groups for Christians trying to kick the habit.

NetAccountability co-founders Brandon Cotter and Scott Covington, both in their early 30s, left jobs in the technology field to start the ministry 2 1/2 years ago.

Since then, NetAccountability has sold more than 5,000 copies of software the pair developed that lets a partner monitor the Web sites visited by the recovering porn user. The software sells for $49 a year.

The billboards have been going up in Dallas over the past few days.

“I’ve seen pornography impact guys all around me,” Cotter said. “I’ve seen it tear up marriages, guys losing their jobs, all over the board. In a lot of cases, they were Christian guys going to church, with otherwise ‘normal lives.'”

Billboards like this are popping up throughout Dallas in an effort to help Christians confront the secret