FIG. 1 is a perspective view of a headboard, showing my new design; FIG. 2 is a front elevational view thereof; the rear elevational view being substantially similar to the view shown in FIG. 3; FIG. 3 is a left side elevational view thereof; the right side elevational view being the mirror image thereof; FIG. 4 is a top plan view thereof; and, FIG. 5 is a bottom plan view thereof.