President Clinton stole a page — that is, a chart or two — from Ross Perot in his first prime time news conference Thursday night. His message of economic hope, and plea for Congress to enact his plan to cut the deficit by $ 500 million, was accompanied by brightly colored charts similar to those used by his former presidential opponent.Unlike Perot, Clinton didn’t pay for the airtime, and it cost him. ABC and CBS didn’t broadcast the news conference live, opting to stick with commercial programming, and NBC pulled away after 25 minutes. CNN covered the news conference from the East Room of the White House in its entirety. It was Clinton’s third session with reporters since the beginning of the week , a fact cited by network officials in deciding to skip the session.