The ornamental design for a risertoiletseat, as shown and described.
FIG. 1 is a perspective view of the riser toilet seat.
FIG. 2 is a front view thereof.
FIG. 3 is a back view thereof
FIG. 4 is a top view thereof.
FIG. 5 is a bottom view thereof
FIG. 6 is a right side view and mirror image of the left side view thereof.
FIG. 7 is a sectional view of the inside front surface of the hole of the toilet seat.
FIG. 8 is a sectional view of the back surface of the hole of the toilet seat; and,
FIG. 9 is a right side view of the inside surface of the hole of the toilet set and a mirror image of the left side view of the inside surface of the hole of the toilet seat.