1. A computer-implemented method comprising: adding a first widget to a design in a design program using a processing system and at the direction of a user, said first widget having an event and an event handler, and said event and said event handler comprising user defined properties; 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; wherein said design is configured to add said second event handler to said second widget when said instantiation of said design is being rendered by said external player; and wherein said design program defines interaction data for said design, said interaction data capable of being rendered by a web browser only after it has been exported from said design program.