President Reagan hailed federal statistics showing that cocaine and marijuana are less popular with high school seniors. "The message is out and America's young people have heard it," Reagan said in his weekly radio address. The President, speaking from Camp David, Md., said all Americans should be heartened by the results of a Health and Human Services Department survey showing a 20% decline in cocaine use last year among high school seniors and young adults, the first significant decrease in 13 years. The survey also found that the use of marijuana and other outlawed substances continued a seven-year decline. "Drugs hurt. Drugs kill. Drug use is nothing to brag about. Stay away from drugs," Reagan said.