function SetHome(obj,vrl){

try{            

   obj.style.behavior='url(#default#homepage)';obj.setHomePage(vrl);

      }

   catch(e){

     if(window.netscape) {

       try { 

netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");

         }

        catch (e) {

          alert("此操作被浏览器拒绝！\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]的值设置为'true',双击即可。");

        }

     var prefs = Components.classes['@mozilla.org/preferences-service;1'].getService(Components.interfaces.nsIPrefBranch);

                        prefs.setCharPref('browser.startup.homepage',vrl);

                 }

        }

}