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With kidnap survivor Elizabeth Smart (search) by his side, President Bush signed a bill Wednesday that institutes a nationwide alert system meant to quickly inform the public of child abductions.

The Amber Alert (search), part of a package of child safety laws signed by Congress earlier this month, was named after 9-year-old Amber Hagerman of Arlington, Texas, who was kidnapped and murdered in 1996.

"We're acting today in her memory and in the memory of so many other girls and boys who lost their lives in innocence from acts of violence and cruelty," Bush said in a Rose Garden ceremony before signing the bill.

Bush began the speech by saying "I am glad you all are here," a typical refrain that took on added meaning as he welcomed to the White House Hagerman's mother and the families of seven others carrying both joyful stories of their children's rescue and tales of heartbreaking losses.

Surrounded by all of the families, Bush said the law marks important progress in preventing child kidnapping and abuse.

"No family should ever have to endure the nightmare of losing a child," Bush said. "Our nation will fight threats against our children."

The centerpiece of the PROTECT Act of 2003 is the expansion of the Amber Alert program from a statewide to a national program that speeds information over radio and television and electronic highway signs in several states.

The legislation provides federal matching grants to states and communities for equipment and training to create a national network.

Among those attending the sunny springtime event were Jacqueline Marris and Tamara Brooks, teenagers abducted at gunpoint in Lancaster, Calif., and rescued 12 hours later.

News of their disappearance led to the first use of the Amber Alert in California and the subsequent sighting of the stolen car they were in. Sheriff's deputies were able to close in on the abductor while he was sleeping and shot him to death when he awakened and pointed a gun at the police.

Elizabeth Smart was found in March, nine months after the Salt Lake City teen was kidnapped at knifepoint from her bedroom. After her recovery, her father Ed Smart, urged Congress to pass quickly just the Amber Alert portion of the bill, fearing the larger measure would get killed in negotiations.

But House Republican lawmakers, specifically, Judiciary Committee Chairman James Sensenbrenner of Wisconsin, insisted that the Amber Alert not be stripped from a larger bill that also strengthened federal criminal penalties for child pornographers, sexual abusers and kidnappers.

Those elements made it into the final measure despite arguments by Democrats that they wanted more time to discuss whether the new law would limit the ability of federal judges to impose their own sentences. The House version passed 400-25; the Senate passed the bill 98-0.

The final outcome pleased Brenda Van Dam, whose 7-year-old daughter Danielle was murdered by a neighbor, who was sentenced to death last January.

"I am very impressed. I knew the Amber Alert bill encompassed more than just the Amber Alert, but I wasn't filled in on how much it did encompass. I am truly impressed. I think this is a step in the right direction but we have a lot more to do," Van Dam told Fox News.

Van Dam added that she isn't sure that the Amber Alert itself would have helped save the life of her daughter, but she does think that had it been made into law earlier it could have saved more lives.

"We need to get ahead of these predators and save more children that way. And I think the stiffer laws for sex offenders, if they are going to be repeat sex offenders, they deserve to be behind bars for the rest of their lives," she said.

Other provisions include: prohibiting soliciting anything represented to be child pornography; making it easier to prosecute sex tour operators and people who travel overseas for sex with minors; allowing federal judges to order supervision of released sex offenders for the rest of their lives; making it illegal to attempt to take or keep a child outside the United States to avoid custody battles; and requiring convicted child pornographers to register in the National Sex Offender Registry.

Earlier in the day, the White House said the Smart family had requested that it not reveal whether Elizabeth, who wore a white ribbon in her hair and stood between her parents, would attend the ceremony. Smart, now 15, was returned to her family March 12; two transients have been charged in her kidnapping.

Bush also awarded Alabama elementary school teacher Betsy Rogers the title of national teacher of the year, kicking off her year as a roving educational ambassador.

The Associated Press contributed to this report.