The basic idea of The Terminal, Steven Spielberg's new film, comes from the story of an Iranian citizen who became trapped in a Paris airport with an invalid passport. He could neither enter France nor go home. With this fact as base, Sacha Gervasi and Jeff Nathanson have fashioned a screenplay for Spielberg--original story by Gervasi and Andrew Niccol--set in the international terminal of Kennedy Airport in New York. That basic idea is stimulating. Airports, as experiences, are haunting.