JS - add element after element

Question

var appendMe=1;
function appendFunction(){
    var parentElement = document.getElementById('main-content');      
    var node = document.createElement("DIV");
    var textnode = document.createTextNode("This was added dinamically");
    node.appendChild(textnode);     
    node.id = 'new-div_' + appendMe;
    var child = parentElement.children[2];
    parentElement.insertBefore(node, child);
    appendMe++;

}