yui_dom_basic.js

//get an element reference, add a click handler
Y.one('#demo').on('click', function(e) {/*handle click*/});

//add content to an element
Y.one('#demo').append(" Additional content added to #demo.");

//listen for any click on any <li> that descends from #demo:
Y.one('#demo').delegate('click', function(e) {/*handle clidk*/}, 'li');

//move #demo to the location of any click on the document
Y.one('document').on('click', function(e) {
    	Y.one('#demo').setXY([e.pageX, e.pageY]);
	}
);