9PM This episode's headline: Advancing on Baghdad; Conversation; On the Homefront. ANCHOR: JIM LEHRER; GUESTS: COL. W. PATRICK LANG: LT. COL. DALE DAVIS; COL. SAMUEL GARDINER;CORRESPONDENTS: KWAME HOLMAN; RAY SUAREZ; SPENCER MICHELS; MARGARET WARNER; GWEN IFILL; TERENCE SMITH; KWAME HOLMAN