1. A computer-implemented method comprising: adding a first widget to a design in a design program at the direction of a user, said first widget having an event and an event handler; adding a second widget to said design; and exporting said design comprising said first widget and said second widget from said design program, said exporting step creating an instantiation of said design that is capable of being rendered by an external player; wherein executing said event handler adds a second event handler to said second widget in said instantiation upon an occurrence defined by said event.