PAVILION, SELSEY. Gaiety is the password for those patrons who wish to see "SPRINGTIME IN THE ROCKIES," when this bright and exhilarating musical - filmed in Technicolor- is screened on Monday, Tuesday and Wednesday. With Betty Grable, John Payne, Carmen Miranda, Cesar Romero and Harry James and his Music Makers coming together, the frivolous plot develops into a gay succession of light-hearted romantic incidents, punctuated by music and laughter. Main feature on Thursday for three days is a stirring picture about the Belgian Resistance Movement during the war, which is based on actual fact. A mission of sabotage is traced from start to finish, and involves six from a catholic priest to a Belgian girl. Robert Beatty, Simone Signoret and Jack Warner are the stars of "AGAINST THE WIND."