获取IFrame表单提交之后的返回值

var doc = document.getElementById('interface_data').contentWindow.document; //'interface_data'是iframe的id

                doc.getElementById('topicid').value = v;

                doc.getElementById('form_addTo').action = action; //'form_addTo'是iframe页面中的form 的id

                doc.getElementById('form_addTo').submit();

                 

                var oFrm = document.getElementById("interface_data");

                oFrm.onload = oFrm.onreadystatechange = function() {

                     if (this.readyState && this.readyState != 'complete') return;

                     else{

                         

                        if (document.all){//IE

                                var sub_con = document.frames["interface_data"].document;

                        }else{//Firefox

                                var sub_con = document.getElementById("interface_data").contentDocument;

                                 

                        }

                                                 

                        sub_con = sub_con.body.innerHTML;  //取得返回值

                        alert(sub_con);

                  }