The SMEventHandler class
allows for developers to register event handlers with just one line of code, without the need to write browser specific code.
alert("Page done loading");
SMEventHandler.AddEventHandler(window, "load", onLoadHandler);
The AddEventHandler function takes three arguments: The element which fires the event, the name of the event (without the "on" prefix - i.e. "onload" becomes "load"), and a reference to the event handler function. Also notice that since most versions of Internet Explorer does not support event capturing, only event bubbling is supported.