autocomplete result is exceeding div

I have an autocomplete with

$("#txtSearch").autocomplete({
    source: function (request, response) {
        $.ajax({
            type: "POST",
            contentType: "application/json; charset=utf-8",
            url: "Evaris.aspx/GetTipMasura",
            data: "{'TipMasura':'" + document.getElementById('txtSearch').value + "'}",
            dataType: "json",
            success: function (data) {
                if (data != null) {
                    response(data.d);
                }
            },
            error: function (result) {
                alert("Error");
            }
        });
    }
});

but the reswult is exceeding their div limits

How do I fix this?