Riley of the Rainbow Division (1928)

Two pals enlist in the army during World War I. Just before they complete training camp and are to be sent overseas, they're scheduled to marry their girlfriends. However, they get in trouble and wind up in the guardhouse. Their girlfriends are determined to get married, however, and in order to accomplish this, they disguise themselves as soldiers and sneak onto the base, where they unwittingly get mixed up with enemy spies trying to gather information.