The ornamental design for a runningboard, as shown and described.
FIG. 1 is an isometric view of my ornamental design for a running board.
FIG. 2 is a top plan view of the design of FIG. 1.
FIG. 3 is a bottom plan view of the design of FIG. 1.
FIG. 4 is a front elevational view of the design of FIG. 1.
FIG. 5 is a rear elevational view of the design of FIG. 1.
FIG. 6 is a right side elevational view of the design of FIG. 1; and,
FIG. 7 is a left side elevational view of the design of FIG. 1.
The broken lines in these drawings serve to illustrate the environment in which the claimed design is associated or serve to define the bounds of the claimed design. The broken lines with dashes of uniform length denote boundaries, and the broken lines with dot-dashes of varying lengths denote environment. The broken lines form no part of the claimed design. The running board is shown broken away in the middle of FIGS. 1-5 to indicate no specific length.