Since inline events are executed as functions you can simply use arguments.
<p id="p" onclick="doSomething.apply(this, arguments)">
and
function doSomething(e) {
if (!e) e = window.event;
// 'e' is the event.
// 'this' is the P element
}
The 'event' that is mentioned in the accepted answer is actually the name of the argument passed to the function. It has nothing to do with the global event.