PHP programming forum. Ask questions or help people concerning PHP code. Don't understand a function? Need help implementing a class? Don't understand a class? Here is where to ask. Remember to do your homework!
Let me just say, were not here to debug your scripts for you. Don't take our precious time and effort around here for granted. At minimum, you should post what you've attempted to solve the solution, such as any debuging information.
What kind of images were you trying to upload? Size of image? Error messages? Anything is better than nothing.
To answer your question with the same effort your given us, likely because your if statements are failing.
You really ought to rewrite the resizing code anyway. It's ignoring the aspect ratio when it generates the smaller image which is going to make the thumbnails look really nasty.