The ornamental design of a top for a popcornmaker, as shown and described.
FIG. 1 is a perspective view of a top for a popcorn maker, with the broken lines representing the environment of use and forming no part of the claim;
FIG. 2 is a a front elevational view of the top for a popcorn maker thereof;
FIG. 3 is a right side elevational view of the top for a popcorn maker thereof; a left side elevational view, not shown is a mirror image of said right side elvational view;
FIG. 4 is a top elevational view of the top for a popcorn maker thereof; and,
FIG. 5 is a rear elevation view of a top for a popcorn maker with the broken lines representing unclaimed portions of the structure.