When an execution request for a predetermined function occurs when a content associated with a certain frame is executed, a definition of the function for which execution is requested is searched for in the content. When the definition of the function is not found in the content, the definition of the function is searched for until the definition of the function is found in a content associated with a parent frame of the frame associated with the content in which the definition has not been found. When the definition of the function is found, predetermined processing is executed based on the found definition of the function.