We claim the ornamental design for a screen, as shown and described.
FIG. 1 is a perspective view of the screen in operation with a vertically-extending flap extending around the back of the chair and interconnected to a horizontally-extending strap for holding a screen portion in place on the chair;
FIG. 2 is a front view of the screen wherein the vertically extending flap is laid upwardly, away from the horizontally-extending strap, to reveal the underside of the flap;
FIG. 3 is a rear view of the screen;
FIG. 4 is a side view of the screen, wherein a left-hand side view, a right-hand side view, a top view, and a bottom view appear the same; and,
FIG. 5 is a cross-sectional view taken through section lines 5—5 shown in FIG. 2.
The broken line showing of the chair is included for the purpose of illustrating use and environment and forms no part of the claimed design.