bundles/org.eclipse.orion.client.core/web/orion/EventTarget.js
function(eventName, listener) {
			if (typeof listener === "function" || listener.handleEvent) {
				this._namedListeners[eventName] = this._namedListeners[eventName] || [];
				this._namedListeners[eventName].push(listener);
			}
		}
function(eventName, listener) {
			if (typeof listener === "function" || listener.handleEvent) {
				this._namedListeners[eventName] = this._namedListeners[eventName] || [];
				this._namedListeners[eventName].push(listener);
			}
		}
function ( eventName , listener ) { if ( typeof listener === "function" || listener . handleEvent ) { this . _namedListeners [ eventName ] = this . _namedListeners [ eventName ] || [ ] ; this . _namedListeners [ eventName ] . push ( listener ) ; } }
Adds an event listener for a named event
@param {String} eventName The event name
@param {Function} listener The function called when an event occurs
Adds an event listener for a named event