During the course of this tutorial you will learn how to provide users with the facility to upload files to a remote server using an HTML form; specifically this tutorial will focus on uploading image files to an Images directory and saving a proportionally-sized thumbnail of the uploaded images in a Thumbs directory. The code presented here is able to identify if an image is landscape or portrait and adjust the dimensions of the generated thumbnail accordingly. This is a very common scenario on a typical e-commerce site where a product list page would show the thumbnail images and the detailed product info page would show the larger image. This tutorial demonstrates how to code the ASP.NET for uploading gif and jpg files.