Appellant removed a screen from a residence window and tried unsuccessfully to open the window with a screwdriver. A jury found him guilty of burglary. The Court of Appeal reversed, finding that appellant was guilty only of attempted first degree burglary because penetration into the area behind a window screen does not amount to an entry of a building within the meaning of the statute, at least when the window is closed and not penetrated. The Supreme Court here reversed the judgment of the Court of Appeal. A window screen is part of the outer boundary of the building for the purposes of burglary. Window screens, which announce that intrusion is unauthorized, do not limit their message to flies but extend it to burglars as well. A dissenting opinion by J. Kennard held that appellant tried, but failed, to enter the house, and was therefore guilty of attempted burglary.