PORTLAND, Ore. -- Craigslist.com creators have agreed to help police crack down on the online sex trade.

The new program is focused on specifically stopping child pornography and child prostitution by changing the way ads are posted in a category called erotic services.

Up until now, ads could be posted in that section for free, but the rules are changing so that anyone who now posts an ad in that section of the site will have to include a phone number and make a payment with a valid credit card.

The site agreed to the change with attorneys general from 43 states including Oregon and Washington.

Police said people were previously able to search for child porn and underage prostitutes from the privacy of their own home by using the section.

Officers said they think this change will cut down on the crime by no longer allowing users to remain anonymous.

Craigslist officials have said they will donate the fee to charity and also agreed to erase ads that have inappropriate content.

Craigslist.com To Crack Down On Sex Trade