The ornamental design for a frame, as shown and described.
FIG. 1 is a perspective view of a frame showing my new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a left side elevational view thereof;
FIG. 5 is a right side elevational view thereof;
FIG. 6 is a top plan view thereof;
FIG. 7 is a bottom plan view thereof;
FIG. 8 is another perspective view thereof; and,
FIG. 9 is yet another perspective view thereof.
The broken lines in the drawings represent portions of the frame that form no part of the claimed design.
The frame is shown with a symbolic break in its length. The appearance of any portion of the frame between the break lines forms no part of the claimed design.