.net

Javascript:

 function fnAddoption()

 {
            var Cnt = parseInt(document.getElementById("<%=hiddencount1.ClientID %>").value);
            var Cid = parseInt(document.getElementById("<%=hidrowid.ClientID %>").value);
            browser = window.navigator.appName;
            var newtr;
            if (browser == "Microsoft Internet Explorer")
                newtr = document.getElementById('Addimg').insertRow();
            else
                newtr = document.getElementById('Addimg').insertRow(Cid + 1);
            var newtd1 = newtr.insertCell(0);
            var newtd2 = newtr.insertCell(1);
            var newtd4 = newtr.insertCell(2);
            var newtd3 = newtr.insertCell(3);
            newtd1.innerHTML = "";
            newtd2.innerHTML += "<td align='right' width='219'><input class='formTxtBox' style='width:210px; height:20px;'  type='file'  id='txtGalleryFile" + (Cid) + "' name ='txtGalleryFile" + (Cid) + "'  class='txt_box_n' contenteditable='false' value='' onKeyDown='return false;'  onKeyPress='return false;'  ></td>";
            newtd2.height = "";

            //newtd2.innerHTML +="<td align='right'>"
            newtd4.innerHTML += "<td align='right' width='219'><input type='button' name='btnDel' value=' -'  style='height:20px;' onClick=fndel1(this.parentNode.parentNode.rowIndex) >";
            newtd4.innerHTML += "<input type='hidden' name='hidImage" + (Cid) + "' id='hidImage" + (Cid) + "' value=''>";
            newtd3.innerHTML += "";
            document.getElementById("<%=hiddencount1.ClientID %>").value = parseInt(document.getElementById("<%=hiddencount1.ClientID %>").value) + 1;
            document.getElementById("<%=hidrowid.ClientID %>").value = parseInt(document.getElementById("<%=hidrowid.ClientID %>").value) + 1;
            return true;


        }

        function fndel1(no, delid)

 {
            if (delid != undefined) {
                document.getElementById('hiddeletIds').value += delid + ",";
            }
            document.getElementById('Addimg').deleteRow(no);
            document.getElementById("<%=hiddencount1.ClientID %>").value = parseInt(document.getElementById("<%=hiddencount1.ClientID %>").value) - 1;
            document.getElementById("<%=hidrowid.ClientID %>").value = parseInt(document.getElementById("<%=hidrowid.ClientID %>").value) - 1;
        }

Using Page:

 <td>
                                            <table cellpadding="0" cellspacing="0" id="Addimg" height="25px" width="200px">
                                                <tr id="trfirst" runat="server">
                                                    <td align="center">
                                                        <asp:FileUpload ID="imageFileUP" runat="server" Width="219px" />
                                                        <td>
                                                            <input type="button" id="btnincress" onclick=" return fnAddoption();" runat="server"
                                                                style="height: 20px; padding-left: 9px; top: 5px; width: 31px;" value="+" name="btnadd" />
                                                        </td>
                                                    </td>
                                                </tr>
                                            </table>
                                            <asp:Label runat="Server" ID="lblgalleyFile" Style="float: left;" Height="18px" Width="82px"></asp:Label>
                                        </td>

C#  Backend Coding
....................................



#region MultipleUploader
        String MultipleUploader()
        {
            HttpFileCollection Files;
            string[] arrCount = null;
            Files = Request.Files;
            arrCount = Files.AllKeys;
            String OldNames = String.Empty;
            String ImageFileNames = String.Empty;
            string filepath = AppDomain.CurrentDomain.BaseDirectory + "Gallery/";
            if (!Directory.Exists(filepath))
            {
                Directory.CreateDirectory(filepath);
            }
            try
            {
                if (System.IO.Path.GetFileName(Files[arrCount[0]].FileName) != "")
                {
                    String tempfile1 = Guid.NewGuid().ToString().Substring(0, 5);
                    Files[arrCount[0]].SaveAs(filepath + tempfile1 + ".jpg");
                    ImageFileNames += tempfile1 + ".jpg" + "^";
                }
                else
                {
                    ImageFileNames += hidrowEditImgFirstRow.Value + "^";
                }


            }
            catch (Exception ex) { }

            for (int i = 1; i < arrCount.Length; i++)
            {
                try
                {
                    String tempname = Guid.NewGuid().ToString().Substring(0, 5);
                    if (System.IO.Path.GetFileName(Files[arrCount[i]].FileName.Replace("^", "")) != "")
                    {
                        Files[arrCount[i]].SaveAs(filepath + tempname + ".jpg");
                        ImageFileNames += tempname + ".jpg" + "^";
                        //DBclass.fnThumbImg(filepath, ImageFileNames, "image");
                    }


                    else
                    {
                        try
                        {
                            ImageFileNames += Request.Form["hidImage" + (i - 1)].ToString() + "^";
                        }
                        catch (Exception ex)
                        {

                        }
                    }
                }
                catch (Exception ex)
                {

                }
            }
            return ImageFileNames.Substring(0, ImageFileNames.Length - 1);

        }
        #endregion




File Name:
..........................


  string Upload = MultipleUploader();