function setHomepage() {   
    var lan = window.location;   
    if (document.all) {   
        document.body.style.behavior = 'url(#default#homepage)';   
        var body = document.body;   
        body.setHomePage(lan.href);   
    } else if (window.sidebar) {   
        if (window.netscape) {   
            try {    
                netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");    
            } catch (e) {   
                alert("该操作被浏览器拒绝，如果想启用该功能，请在地址栏内输入 about:config,然后将项 signed.applets.codebase_principal_support 值该为true");    
            }   
        }   
        var prefs = Components.classes['@mozilla.org/preferences-service;1'].getService(Components. interfaces.nsIPrefBranch);   
        prefs.setCharPref('browser.startup.homepage', lan.href);   
    }   
}