If your IIS (Internet Information Server) cannot interpret an ASPX file and returns an error, there is a big chance that you did not register ASP.Net in IIS.
To do so, just run the commend aspnet_regiis and it handles everything behind the scenes including adding a mime type of ASPX type to IIS so that it will be able to interpret it.
Asp Jpeg is a server component that will help your ASP or ASP.NET applications with all their image management needs. With Asp Jpeg, you can create high-quality thumbnails, logo-stamp photographs, extract metadata information from images, crop, enhance, rotate, convert, and much more. Of course, resizing images in webpages will not give you problems calculating the height based on the width since you can just input the width and the height will automatically be calculated.
However, if you wish to have high quality resized images, Asp Jpeg is a good component for that purpose. It is not free though, so you will have to purchase it. If you have one, read on. Using the component is pretty simple. Check out the code below in VBScript.