The ornamental design for a storagebox, as shown and described.
FIG. 1 is a perspective view of a storage box showing my new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof; and,
FIG. 4 is a top plan view thereof.
The broken line showing of the wall studs in FIGS. 1-4 is for illustrative
purposes only and forms no part of the claimed design. The broken line
showing of the chain and hangers in FIGS. 1-4 is for illustrative purposes
only, merely showing the type of hardware which can be used, and forms no
part of the claimed design.