JS实现同一DOM元素上onClick事件与onDblClick事件并存

<script type="text/javascript">
 var clickTimer = null;
 function _click(){
   if(clickTimer) {
     window.clearTimeout(clickTimer);
     clickTimer = null;
   }
   clickTimer = window.setTimeout(function(){
      // your click process code here
      alert("你单击了我");
   }, 300);
 }
  function _dblclick(){
   if(clickTimer) {
     window.clearTimeout(clickTimer);
     clickTimer = null;
   }
   // your click process code here
   alert("你双击了我");
 }
</script>
<button onclick="_click();" ondblclick="_dblclick();">单击或双击我</button>