问题描述：IE浏览器加载Iframe跨域访问后Cookie丢失，用户登录状态失效

解决方法：在PHP中加入以下代码即可解决

   header("Access-Control-Allow-Origin:*");
   header("Access-Control-Allow-Credentials: true");
   header('P3P:CP="IDC DSP COR ADM DEVi TAIi PSA PSD IVAi IVDi CONi HIS OUR IND CNT"');