JavaScript 复制内容到剪贴板

<html>  
<head>  
<title>Selector</title>  
<script language="javascript">  
   var i = 0 ;   
   function copyContact(){  
       var contat = document.getElementById("inquiryContact1").value;  
       window.clipboardData.setData('text', contat);  
       if(window.clipboardData.getData('text')==''){  
           if(i==1){  
               alert("复制失败，请手动Ctrl+C快捷键复制！");  
           }else{  
                alert("复制失败，请重新复制！");  
                i = 1;  
            }  
        }else{  
             alert("内容已经复制到剪贴板！");  
        }  
    }  
</script>   
<body>  
        <input id='inquiryContact1' ></input>
      <input type="button" id="button" name="button" value="复制" onclick="copyContact()"/>  
  
</body>  
</html>