ASP upload image og resize

CSharp kode 

 using System;
 using System.Collections.Generic;
 using System.Drawing;
 using System.Drawing.Imaging;
 using System.IO;
 using System.Linq;
 using System.Web;
 using System.Web.UI;
 using System.Web.UI.HtmlControls;
 using System.Web.UI.WebControls;
 
 public partial class _Default : System.Web.UI.Page
 {
     private static string pathImg = @"images/";
     private static string pathThumbs = pathImg + @"thumbs/";
     private static string pathActive = pathImg + @"actives/";
     private static string pathOverlay = @"system/overlay.png";
     private static int thumbnailHeight = 66;
     private static int thumbnailMaxWidth = 100;
 
     /// <summary>
     /// Generates thumbnails for a specified image
     /// </summary>
     /// <param name="file">Image to be resized</param>
     private void GenerateThumb(FileInfo file)
     {
         //Opens the image and specifies the type/format
         Bitmap bmp = new Bitmap(file.FullName);
         ImageFormat format = bmp.RawFormat;
 
         //Variables for calculating new size
         decimal ratio;
         int newWidth = thumbnailMaxWidth;
         int newHeight = thumbnailHeight;
 
         //Calculating new size
         if (bmp.Width > bmp.Height)
         {
             ratio = (decimal)newWidth / bmp.Width;
             newHeight = Convert.ToInt32(bmp.Height * ratio);
         }
         else
         {
             ratio = (decimal) newHeight / bmp.Height;
             newWidth = Convert.ToInt32(bmp.Width * ratio);
         }
 
         //Preparing to draw thumbnail in a new bitmap!
         Bitmap tmb = new Bitmap(newWidth, newHeight);
         Graphics g = Graphics.FromImage(tmb);
         
         //Quality and method
         g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
 
         //Draw the thumbnail
         g.DrawImage(bmp, 0, 0, newWidth, newHeight);
 
         //Gets rid of garbage - nessarily before saving!
         g.Dispose();
         bmp.Dispose();
 
         //Saving the thumbnail
         tmb.Save(Page.MapPath(pathThumbs) + file.Name, format);
 
         //Opens the overlay, creates a new bitmap and prepares for drawing
         Bitmap bmpOverlay = new Bitmap(Server.MapPath(pathOverlay));
         Bitmap tmbActive = new Bitmap(newWidth, newHeight);
         g = Graphics.FromImage(tmbActive);
 
         //Same quality and method as above
         g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
 
         //Drawing twhice, first copy the thumbnail, then the overlay
         g.DrawImage(tmb, 0, 0, newWidth, newHeight);
         g.DrawImage(bmpOverlay, 0, 0, newWidth, newHeight);
 
         //Getting rid of garbage - Where is my butler?!
         g.Dispose();
         tmb.Dispose();
         bmpOverlay.Dispose();
 
         //Saves the thumbnail with overlay!
         tmbActive.Save(Page.MapPath(pathActive) + file.Name, format);
 
         //Cleaning up
         tmbActive.Dispose();
     }
 }