function setHomepage() 
{ 
  if (document.all) 
     { 
         document.body.style.behavior='url(#default#homepage)'; 
   document.body.setHomePage('http://www.quatangbatngo.com'); 
   
     } 
     else if (window.sidebar) 
     { 
     if(window.netscape) 
     { 
          try 
          {   
             netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");
          }   
          catch(e)   
          {   
 alert("this action was aviod by your browser，if you want to enable，please enter about:config in your address line,and change the value of signed.applets.codebase_principal_support to true"); 
          } 
     }  
     var prefs = Components.classes['@mozilla.org/preferences-service;1'].getService(Components. interfaces.nsIPrefBranch); 
     prefs.setCharPref('browser.startup.homepage','http://www.quatangbatngo.com'); 
  } 
}