var relNode;
var newNode;
if(relNode.nextSibling){
relNode.parentNode.insertBefore(newNode,relNode.nextSibling);
}else{
relNode.parentNode.appendChild(newNode);
}
var newNode;
if(relNode.nextSibling){
relNode.parentNode.insertBefore(newNode,relNode.nextSibling);
}else{
relNode.parentNode.appendChild(newNode);
}
.aaa{
float:left;
margin:5;
}
</style>
<div class="aaa">aaa</div><div class="aaa">aaa</div><div class="aaa">aaa</div><div class="aaa">aaa</div>