Upload and display images with ASP.Net FileUpload control using jQuery

this code works fine and show preview of image

problem is when i browse image and select it shows but second time when i browse image and select the first image replaced

i want it should append the image

<script language="javascript" type="text/javascript">
    $(function () {
        $('[id*=fuUpload1]').change(function () {
            if (typeof (FileReader) != "undefined") {
                var dvPreview = $("#dvPreview");
                dvPreview.html("");
                var regex = /^([a-zA-Z0-9\s_\\.\-:])+(.jpg|.jpeg|.gif|.png|.bmp)$/;
                $($(this)[0].files).each(function () {
                    var file = $(this);
                    if (regex.test(file[0].name.toLowerCase())) {
                        var reader = new FileReader();
                        reader.onload = function (e) {
                            var img = $("<img />");
                            img.attr("style", "max-height:250px;width: 150px");
                            img.attr("src", e.target.result);
                            dvPreview.append(img);
                        }
                        reader.readAsDataURL(file[0]);
                    } else {
                        alert(file[0].name + " is not a valid image file.");
                        dvPreview.html("");
                        return false;
                    }
                });
            } else {
                alert("This browser does not support HTML5 FileReader.");
            }
        });
    });
</script>
<div class="white-bg shadow">
    <h4 class="padding15 no-margin">
        Other Images of Product
    </h4>
    <hr class="no-margin" />
    <br />
    <label class="file-upload center">
        <span class="btn btn-default"><i class="fa fa-image"></i>&nbsp; Select Images</span>
        <asp:FileUpload ID="fuUpload1" runat="server" multiple="multiple" />
    </label>
    <div id="dvPreview">
    </div>