js动态添加div和删除div

<div id="container">
<input type="text" id="test"><button id="add">添加</button>
</div>
<div><p>tetse</p></div>
<script type="text/javascript">
var add = document.getElementById('add');
var container =document.getElementById('container');
var node=container.nextSibling;
add.onclick = function(){
oDiv = document.createElement('div');
oDiv.innerHTML = "<div id='container1'><input type='text' id='test'><input type='button' onclick='test(this)' value='减少'/></div>";
container.parentNode.insertBefore(oDiv, node)
node=oDiv.nextSibling;

}
function test(test){
test.parentNode.parentNode.removeChild(test.parentNode);
}
</script>
</body>