How to handle timeout error on ajax call

See more:

Ajax

jQuery

MVC3

I want to handle timeout error on ajax call where i have set session timeout to 1 minute like..

<authentication mode="Forms">
        <forms loginUrl="~/User/Login"  timeout="1" />
    </authentication>

and my call for every ajax request is like..

$.ajax({

            url: '../Document/getData?did=' + docid2,

            beforeSend: function () {

                $("#DialogData").empty().html('<p class="Loadimg"></p>');
            },
            success: function (result) {

                $("#DialogData").load('../Document/getData?did=' + docid2);
            },

            error: function (req, status, xhr) {
                alert(xhr);
                //for Timeout Error
                if (status == "timeout") {

                    $("#DialogData").empty().html('<p>Plese Try Again</p><');
                }


                if (status == "error") {
                    //for Page Not Found Invalid URL
                    if (xhr == "Not Found") {
                        
                    }
                    //for server error which is from controller
                    if (xhr == "Internal Server Error") {
                        
                    }
                } //if error
            } //error
        }); //Ajax

but on timeout i get internal server error...i want to handle timeout error differently than other error so what should i do..