兼容IE和Firefox的复制页面地址到粘贴板

<script type="text/javascript">
/*
*Ie && Firefox CopyToClipBoard
*
*/ 
function copyToClipBoard() {
    var txt = window.location.toString();
        //txt += document.title;
    if(window.clipboardData) { 
        window.clipboardData.clearData();   
        window.clipboardData.setData("Text",txt);
    }else if(navigator.userAgent.indexOf("Opera") != -1) {   
        window.location = txt;   
    } else if (window.netscape) {   
        try {   
            netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");   
        } catch (e) {   
            alert("被浏览器拒绝！\n请在浏览器地址栏输入'about:config'并回车\n然后将'signed.applets.codebase_principal_support'设置为'true'");   
        }   
        var clip = Components.classes['@mozilla.org/widget/clipboard;1'].createInstance(Components.interfaces.nsIClipboard);   
        if (!clip)   
            return;   
        var trans = Components.classes['@mozilla.org/widget/transferable;1'].createInstance(Components.interfaces.nsITransferable);   
        if (!trans)   
            return;   
        trans.addDataFlavor('text/unicode');   
        var str = new Object();   
        var len = new Object();   
        var str = Components.classes["@mozilla.org/supports-string;1"].createInstance(Components.interfaces.nsISupportsString);   
        var copytext = txt;   
        str.data = copytext;   
        trans.setTransferData("text/unicode",str,copytext.length*2);   
        var clipid = Components.interfaces.nsIClipboard;   
        if (!clip)   
            return false;   
        clip.setData(trans,null,clipid.kGlobalClipboard);
    } 
    alert("你已经成功复制本帖地址，请直接粘贴推荐给你的朋友!");
}
</script> 
<a href="javascript:;" onClick="copyToClipBoard();">推荐给朋友</a>