1:  <script type="text/javascript">

   2:   

   3:          function getContents(iframe) {

   4:              try {

   5:                  // Make sure the iframe's window & document are loaded.

   6:                  if (!iframe.contentWindow || !iframe.contentWindow.document) {

   7:                      console.log("no contentwindow");

   8:                      return null;

   9:                  }

  10:   

  11:                  console.info("window.name=" + iframe.contentWindow.name);

  12:                  // Get the response from window.name

  13:                  return iframe.contentWindow.name;

  14:              } catch (e) {

  15:                  console.error(e);

  16:                  return null;

  17:              }

  18:          }

  19:   

  20:   

  21:          //getContents(this);

  22:   

  23:   

  24:          function test() {

  25:              var doc = document;

  26:              var iframe = doc.createElement('iframe');

  27:              doc.body.appendChild(iframe);

  28:   

  29:              var form = doc.createElement('form');

  30:              doc.body.appendChild(form);

  31:   

  32:              var requestId = "__Go";

  33:              iframe.contentWindow.name = requestId;

  34:              form.target = requestId;

  35:              form.action = "http://castest.youxituan.com/cas/JsLogin";

  36:              form.method = "post";

  37:              var isFirst;

  38:              var time = 0;

  39:              iframe.onload = function () {

  40:                  time++;

  41:                  console.info("time=" + time);

  42:                  if (time == 1) {

  43:                      console.info("first" + iframe.src);

  44:                      iframe.contentWindow.location = 'about:blank';

  45:   

  46:                      //iframe.contentWindow.document.write(".....");

  47:                      isFirst = false;

  48:                  } if (time == 2) {

  49:                      console.info("not first");

  50:                      window.alert(iframe.contentWindow.name);

  51:   

  52:                      //iframe.contentWindow.document.write('');

  53:                      //iframe.contentWindow.close();

  54:                      //document.body.removeChild(iframe);

  55:   

  56:                      //iframe.src = '';

  57:                      iframe = null;

  58:                  }

  59:                  console.log("onload");

  60:                  getContents(iframe);

  61:   

  62:              };

  63:              iframe.onreadystatechange = function () {

  64:                  console.log("onreadystatechange");

  65:                  getContents(iframe);

  66:              };

  67:   

  68:              form.submit();

  69:          }

  70:   

  71:   

  72:          $(function () {

  73:              test();

  74:          });

  75:   

  76:   

  77:      </script>