1. A computer program product for facilitating screen readers of online electronic documents, the computer program product comprising: a computer readable storage medium having computer readable program code embodied therewith, the computer readable program code comprising: computer readable program code configured to generate a structured electronic document including markup language code and scripting language code whose execution is triggered by an occurrence of an event associated with execution of the markup language code, the execution of the scripting language code producing a web presentation unrecognized by a screen reader software program; computer readable program code configured to define a mapping of one or more functions of the screen reader software program to one or more functions performed by the scripting language code that produces the unrecognized web presentation when the scripting language code is executed in response to the occurrence of the event; and computer readable program code configured to incorporate the mapping of functions within the structured electronic document when the structured electronic document is initially generated, before the structured electronic document is posted on a web server and made available for subsequent downloading and display, wherein the mapping of functions specifies text obtained from the unrecognized web presentation to be read aloud by the screen reader.