Someone

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Net.Mail;
using System.Text;
using System.IO;
using System.Drawing;


public partial class Default3 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
       // ArrayList fileList = (ArrayList)Session["Session"];
        if (!IsPostBack)
        {
            // uploading files

            Boolean fileOK = false;
            String path = Server.MapPath("~/UploadedImages/");
            if (FileUpload1.HasFile)
            {
                String fileExtension =
                    System.IO.Path.GetExtension(FileUpload1.FileName).ToLower();
                String[] allowedExtensions = 
                { ".gif", ".png", ".jpeg", ".jpg" };
                for (int i = 0; i < allowedExtensions.Length; i++)
                {
                    if (fileExtension == allowedExtensions[i])
                    {
                        fileOK = true;
                    }
                }
            }

            if (fileOK)
            {
                try
                {
                    FileUpload1.PostedFile.SaveAs(path
                        + FileUpload1.FileName);
                    Label1.Text = "File uploaded!";
                }
                catch (Exception ex)
                {
                    Label1.Text = "File could not be uploaded.";
                }
            }
            else
            {
                Label1.Text = "Cannot accept files of this type.";
            }


            // checking if the folder exists and transfering 
            //the list offiles into an arraylist

            ArrayList fileList = (ArrayList)Session["session"];
            if (!Directory.Exists(Request.MapPath("Images")))
            {
                Directory.CreateDirectory(Request.MapPath("Images"));
            }
            Session["session"] = fileList;
            ArrayList images = new ArrayList();
            DirectoryInfo di = new DirectoryInfo("Images");
            FileInfo[] rgFiles = di.GetFiles("*.jpg");
            foreach (FileInfo fi in rgFiles)
            {
                string[] newarr = new string[5];

                for (int i = 0, j = 0; i < rgFiles.Length; i++, j++)
                {
                    newarr[j] = rgFiles[i].ToString();
                }
                images.Add(newarr);
                Session["session"] = images;
            // Response.Write("<br><a href=" + fi.Name + ">" + fi.Name + "</a>");
            }

            //ArrayList images = new ArrayList();
            //DirectoryInfo di = new DirectoryInfo("Images");
            //ArrayList files = di.GetFiles();

            //ArrayList fileList = (ArrayList)Session["Session"];

        } 
        Response.Write(((ArrayList)Session["Session"]).Count);

    }

    protected void btnEmail_Click(object sender, EventArgs e)
    {
        ArrayList img = (ArrayList)Session["session"];
        MailMessage mail = new MailMessage("poopinder@gmail.com",
             txtEmail.Text, "Email Message", " This message is sent using .net");

        Attachment atch1;
        atch1 = new Attachment(Request.MapPath("Images"));
        mail.Attachments.Add(atch1 + img[i]);
        // atch2 = new Attachment(Request.MapPath("email.aspx"));
        // mail.Attachments.Add(atch2);
        mail.BodyEncoding = Encoding.ASCII;
        mail.IsBodyHtml = false;
        // I am using IIS SMTP service . You can use your ISP email if allowed.

        SmtpClient client = new SmtpClient("127.0.0.1");

        // Add credentials if the SMTP server requires them.

        // You can  use an smtp server even if you have SMTP service              ' installed on your machine 
        try
        {

            client.Send(mail);
        }
        catch (Exception ex)
        {
            Response.Write(ex.ToString());
        }





    }
    protected void btnPrevious_Click(object sender, EventArgs e)
    {

        if (Directory.Exists(Request.MapPath("Images")))
        {
            
           // DirectoryInfo di = new DirectoryInfo("Images");

            //String obj = new string(di);
           // obj.IndexOf(0);

            //if dir exists then load it to an obj
            //then get the index of the obj 
            //which will indicate to the current index of the current file
            //for (int i = 0; i < di.GetFiles().Length; i--)
            //{  }
        }
    }

    protected void btnUpload_Click(object sender, EventArgs e)
    {
        HttpPostedFile file = File1.PostedFile;
        // extract the file name only and ignore the rest of the path


        string fileName = file.FileName.Substring(file.FileName.LastIndexOf("\\") + 1);



        System.Drawing.Image img = System.Drawing.Image.FromStream(file.InputStream);


        Bitmap bitmap = new Bitmap(img, img.Width, img.Height);
        try
        {
            bitmap.Save(Request.MapPath(fileName), img.RawFormat);
            Response.Write("file is saved");
        }
        catch (Exception ex)
        {
            Response.Write(ex.ToString());
        }


 

    }
}