Image Handling In ASP.NET

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

using System.Drawing;
public partial class CreatingThumbnailImage : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void btnCreateThumb_Click(object sender, EventArgs e)
    {
        int width = 0;
        int height = 0;
        byte[] image = FileUpload1.FileBytes;
        Int32.TryParse(txtDWidth.Text, out width);
        Int32.TryParse(txtDHeight.Text, out height);
        ImageHandler imageHandler = new ImageHandler();
        bool maintainAR = cbxAspectRation.Checked;
        //calling CreateThumbnail Method to create thumb images
        //it returns Bitmap Image. 
        Bitmap bmp = imageHandler.CreateThumbnail(image, maintainAR, width, height);
        if (bmp != null)
        {
            //creating a file name with guid.
            string fileName = Guid.NewGuid().ToString() + ".jpg";
            //saving in current root folder.
            bmp.Save(Server.MapPath(fileName));
            //set image controls ImageUrl to saved Image, this is to view the thumbnail image
            Image1.ImageUrl = fileName;
        }
        else
        {
            //exception part
            if (imageHandler.havException)
            {
                Response.Write(imageHandler.ExceptionMessage);
            }
        }
    }
}