从PHP到Javascript，再次进入PHP并设置Sessions

我正在尝试解决我遇到的这个问题。问题是，当有人想登录到管理面板时，我会使用此代码：

 <script>
    function myFunction() {
       //alert('you can type now, end with enter');
       $("#test").focus();
    }
    $(document).ready(function() {
        $("form").submit(function(e) {
            e.preventDefault();
           // alert($("#test").val());
           var email = $("#test").val();
           if(email==''){
 // alert("Error.");
 sweetAlert("Oops...", "Error!", "error");
} else {
$.post("sess.php",{ code1: code},
      function(data) {
     // alert(data);
     // swal(data);
     if((data)=="1") {
      swal("Welcome!", "Please wait!", "success")
     } else {
        sweetAlert("Oops...", "Something went wrong.", "error");
     }
      $('#form')[0].reset(); //To reset form fields
      });
    }

        });
    });
    </script>

Sess.php如下所示：

<?php
include("conn.php");
?>
<?php
include("ipcheck.php");

$code2=htmlEntities($_POST['code1'], ENT_QUOTES);
$info = explode("-", $code2);
$username = $info[0];
$password = $info[1];
 $_POST = db_escape($_POST);

  $sql = "SELECT id FROM adminusers
         WHERE user='{$username}'
         AND pass='$password'";
  $result = mysql_query($sql);
  if (mysql_num_rows($result) == 0){


    echo "2";

    exit;
  }
  // Session for user
  $_SESSION['sess_id'] = mysql_result($result, 0, 'id');
  $_SESSION['sess_user'] = $username;

// DAtabse going on here.


    echo "1";

  exit;
?>

因此，如果用户名和密码正确，则登录成功，并且这些会话设置在sess.hp:中

  $_SESSION['sess_id'] = mysql_result($result, 0, 'id');
      $_SESSION['sess_user'] = $username;

我的问题是，我如何使用javascript将通过sess.php为用户设置的会话返回到index.php，这样我就可以在index.php中而不是在sess.php中设置会话？