<script type="text/javascript" language="javascript">
function readTxt() 

    alert(window.clipboardData.getData("text")); 

function setTxt() 

    var t=document.getElementById("txt"); 
    t.select(); 
    window.clipboardData.setData('text',t.createTextRange().text); 

</script>
<body>
    <form id="form1" runat="server">
        <div>
        <input name="txt" value="测试" /> 
        <input type="button" value="复制" onclick="setTxt()" /> 
        <input type="button" value="读取" onclick="readTxt()" /> 
        </div>
    </form>
</body>