The ornamental design for a panelbed, as shown and described.
FIG. 1 is a perspective view of a panel bed according to an embodiment of the invention.
FIG. 2 is an end view of one headboard of a panel bed according to an embodiment of the invention.
FIG. 3 is an end view of the other headboard of a panel bed according to an embodiment of the invention.
FIG. 4 is a side view of a panel bed according to an embodiment of the invention, the view from the opposite side being a mirror-image thereof; and,
FIG. 5 is an overhead view of a panel bed according to an embodiment of the invention.
The broken lines are for environmental purposes only and form no part of the claimed design. The headboard and footboard are shown separately for convenience of illustration.