jQuery code working in FF, Chrome, not in IE

Question

I have a small snippet of code, this:

$(document).ready(function () {
                $("#check").blur(function () {
                    var member = check.value;
                    $('#loading-image').show("fast");
                    $.getJSON('/Endpoint/MemberName/' + member, function (result) {
                        //  var data = JSON.parse(result);
                        var json = result;
                        if (json.result.length != 0) {
                            $("div#preload h2").html("Nombre: " + json.result[0].fullName);
                            jQuery('#services').show("fast");
                        }
                        else {
                            $("div#preload h2").html("No encontrado!");
                            jQuery('#services').hide("fast");
                        }
                        $('#loading-image').fadeOut("fast");

                    });
                });
            });

In Firefox and Chrome the snippet is working as intended, yet in IE browsers I get the following error:

SCRIPT5009: 'check' is undefined

Any idea on what could help me solve this issue?

EDIT: Added check textbox field:

            <div class="input-group col-md-12">
                <input type="text" class="form-control input-lg" placeholder="Buscar numero de socio" id="check" name="check" />
                <span class="input-group-btn">
                    <button class="btn btn-info btn-lg" type="button">
                        <i class="glyphicon glyphicon-search"></i>
                    </button>
                    <button class="btn btn-primary btn-lg" type="button" data-toggle="modal" data-target="#myModal">
                        <i class="glyphicon glyphicon-plus"></i> Añadir Cliente sin Cuenta
                    </button>
                </span>
            </div>

Answer 1

var member = this.value;
var member = $(this).val();