js拖拽

<style type="text/css">
#div1 {width:300px;height:70px;padding:10px;border:1px solid #aaaaaa;}
</style>
<script type="text/javascript">
    function allowDrop(ev){
        ev.preventDefault();
    }
    function drag(ev){
        ev.dataTransfer.setData("Text",ev.target.id);
    }
    function drop(ev){
        ev.preventDefault();
        var data=ev.dataTransfer.getData("Text");
        ev.target.appendChild(document.getElementById(data));
    }
</script>
<div id="div1" ondrop="drop(event)" ondragover="allowDrop(event)"></div>
<img id="drag1" src="http://static.cnblogs.com/images/adminlogo.gif" draggable="true" ondragstart="drag(event)" />