网页防重复提交

 <script language="javascript">    
    var checkSubmitFlg = false;    
    function checkSubmit() {      
        if (!checkSubmitFlg) {  
        checkSubmitFlg = true;      
        return true;   
        }else{ 
         alert("不能重复提交"); 
         return false; 
        } 
     } 
</script> 

<form action="XXXX" method="POST"   onsubmit="return     checkSubmit()"> 
  内容:<input type="text" name="content" value=""/><br> 
  <input type="submit" value="提交"><br> 
</form>