$('#btn_login').click(function() {

            var mid = $('#txt_mid').val();

            var psw = $('#txt_psw').val();

            $.ajax({

                type : "POST",

                url : "/BoardProject/login.ref",

                data : "mid=" + mid + "&psw=" + psw,

                dataType : "text",

                success : function(data, textStatus, xhr) {

                    if (data == 'loginFail') {

                        alert('로그인에 실패하였습니다.')

                    } else {

                        window.location.href = 'main.jsp';

                    }

                },

                error : function(request, status, error) {

                    alert("code:" + request.status + "\n" + "error:" + error);

                }

            })

        });