//设为首页
        function setHome(obj, url) {
            try {
                obj.style.behavior = 'url' + '(#default#homepage)';
                obj.setHomePage(url);
            }
            catch (e) {
                if (window.netscape) {
                    try {
                        netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");
                    }
                    catch (e) {
                        alert("抱歉！您的浏览器不支持直接设为首页。请在浏览器地址栏输入“about:config”并回车然后将[signed.applets.codebase_principal_support]设置为“true”，点击“加入收藏”后忽略安全提示，即可设置成功。");
                    }
                    var prefs = Components.classes['@mozilla.org/preferences-service;1'].getService(Components.interfaces.nsIPrefBranch);
                    prefs.setCharPref('browser.startup.homepage', url);
                }
            }
        }