js跨域post请求

function funPostBack(srvMethod){
        /*
        var contentNR=$(document.getElementById("reportFrame").contentWindow.document).find("#content-container").html();
         contentNR=$("#x").text(contentNR).html();
        contentNR=contentNR.substring(0,400000);
        if(exec_obj==null){
            exec_obj = document.createElement('iframe');
            exec_obj.name = 'tmp_frame';
            exec_obj.src = postbackUrl+"?parms="+contentNR;
            exec_obj.style.display = 'none';
            document.body.appendChild(exec_obj);
        }else{
            exec_obj.src = postbackUrl+"?parms="+contentNR;
        }*/
        
        var contentNR=$(document.getElementById("reportFrame").contentWindow.document).find("#content-container div.pageContentDIV.contentDIV").html();
        if(document.getElementById("SMAL")!=null)
        {
            document.getElementById("SMAL").remove();//首先删除
        }
        var form ="<form action='"+postbackUrl+"' method='post'>" +
                "<input type='hidden' name='parms' value=''/> " +
                "<input type='hidden' name='srvMethod' value=''/> " +
                "</form> ";
        $("body").append("<iframe id='SMAL' name='SMAL' style='display: none'></iframe>");//载入iframe
        $( "#SMAL" ).contents().find('body').html(form);//将form表单塞入iframe;
        $( "#SMAL" ).contents().find("form input[name='parms']").val(contentNR);        
        $( "#SMAL" ).contents().find("form input[name='method']").val(srvMethod);
        $( "#SMAL" ).contents().find('form').submit();
    }