function copyToClipboard(txt) { 
            if (window.clipboardData) { 
                window.clipboardData.clearData(); 
                clipboardData.setData("Text", txt); 
                alert("复制成功！"); 
 
            } 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("复制成功！"); 
            } 
        }