ST. LOUIS (AP) _ President Clinton said Thursday he improvised part of his address to Congress a day earlier ''off the top of my head and from the bottom of my heart.''

Nobody knows that better than Staff Sgt. Rodney Kipling. And nobody appreciates Kipling's efforts more than Clinton.

Kipling was the offstage technician scrolling a script of Clinton's speech on a TelePrompTer, projecting the address onto a plexiglass screen for the president to read.

Clinton made Kipling's job difficult by making major deviations from his prepared remarks. Yet, Kipling was able to stay with the president and lost him only once, White House Press Secretary Dee Dee Myers said.

She said Clinton returned to the White House Wednesday night saying, ''That guy was great. I can't believe he stayed with me.'' The president called Kipling about 11:30 p.m. Thursday to express thanks.