ctx 输出为nutzsite/

function login() {
    console.log(ctx);
	$.modal.loading($("#btnSubmit").data("loading"));
	var username = $.common.trim($("input[name='username']").val());
    var password = $.common.trim($("input[name='password']").val());
    var validateCode = $("input[name='validateCode']").val();
    var rememberMe = $("input[name='rememberme']").is(':checked');
    $.ajax({
        type: "post",
        url: ctx + "login/login",
        data: {
            "username": username,
            "password": password,
            "validateCode" : validateCode,
            "rememberMe": rememberMe,
            "update": true
        },
        success: function(r) {
            if (r.code == 0) {
                location.href = 'index';
            } else {
            	$.modal.closeLoading();
            	$('.imgcode').click();
            	$(".code").val("");
            	$.modal.msg(r.msg);
            }
        }
    });
}

请求地址却变成 http://localhost:8080/nutzsite/nutzsite/login/login
404
这个问题 困扰我好久
怎么 解决好