 CONT: Bettys costume undergoes numerous changes from dirty to clean  and clean to dirty, as well as completeness. When she and Wally  first get into the dance, Wally pulls her blue jacket off her and  wraps it around Cpl.Sitarskys head. For the rest of the movie, she  has the jacket back on. While Betty and Sitarsky are rolling around  underneath the truck, her skirt is very dirty. The next time you see  her, it still dirty, but not as dirty as it was in the previous  scene. When Betty is shown at her house the morning after the attack  by the Japanese sub, her entire outfit is completely clean.