The ornamental design for a casing for handdryer, as shown and described.
FIG. 1 is a front, right perspective view of a casing for hand dryer
showing my new design, the rear of the casing being hollow and of constant
thickness;
FIG. 2 is a top plan view;
FIG. 3 is a bottom plan view;
FIG. 4 is a front elevational view;
FIG. 5 is a right side elevational view, the opposite side being a mirror
image thereto.