Image resize using GetThumbnailImage Function

Image resize using .GetThumbnailImage Function

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI.HtmlControls;
using System.IO;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO.Compression;
using System.Drawing.Drawing2D;


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

Image thumbnailImage;
Bitmap originalImage;

originalImage = new Bitmap("E:\\Retreat.jpg");
int imgHeight = originalImage.Height;
int imgWidht = originalImage.Width;
string format = Convert.ToString(originalImage.RawFormat);
ImageFormat imageFormat;

switch (format)
{
case ("gif"):
imageFormat = ImageFormat.Gif;
break;
default:
imageFormat = ImageFormat.Jpeg;
format = "jpg";
break;
}

if (imgWidht == 0)
{ imgWidht = 100; }

if (imgHeight == 0)
{ imgHeight = imgWidht; }

string ImageSavePath = "E:\\jj1234.jpg";
thumbnailImage = originalImage.GetThumbnailImage(imgWidht, imgHeight, new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailImageAbortDelegate), IntPtr.Zero);
thumbnailImage.Save(ImageSavePath, imageFormat);
originalImage.Dispose();
}
protected static bool ThumbnailImageAbortDelegate() { return false; }
}