Spring Controller + Ajax return String

I want to return String from Spring MVC Controller to Ajax. It is not working as expected and gives error.

My Ajax codes for this:

function ajaxRequest(item) {

    $.ajax({
        type: "POST",
        url: "/myPage",
        data: {
           item: item
        },
        success: function (html) {

            alert(html);
        },
        error: function(e) {
            console.log("Error:" + e);
        }
    });

}

My Controller:

@RequestMapping(value = "/myPage", method= RequestMethod.POST, produces="text/plain")
public @ResponseBody String myController(HttpServletRequest request) {
String myItem = request.getParameter("item");   

...

return myItem + "bla bla bla";
}

Chrome console result:

POST http://localhost:8080/myPage 406 (Not Acceptable) jquery.js
Error:[object XMLHttpRequest] 

What am i missing here?