Add onclick event
// jQuery
$("#myElm").click(function(){
alert("Hello world");
});
// Pure javascript
document.getElementById("myElm").addEventListener("click", function() {
alert("Hello world!");
}, false);
Get child node by index
//jQuery
var child = $("#myElm").eq(2);
// Pure javascript
var child = document.getElementById("myElm").childNodes.item(2);