Element.prototype.appendAfter = function(element) code example
Example: javscript insert element after another
//insert new Element after some reference Element
function insertAfter(newElement, referenceElement) {
referenceElement.parentNode.insertBefore(newElement, referenceElement.nextSibling);
}
//example usage
var newElement = document.createElement("div");
newElement.innerHTML = "my New Div Text";
var myCurrentElement= document.getElementById("myElementID");
insertAfter(newElement, myCurrentElement);