I got an error message when I tried to upload a photograph

Does the error message look like this: “An HTTP error 0 occurred. /node_images/js”?

There are limitations on the size and type of photographs that can be uploaded. It is likely your photograph is too big. It must be less than 500kb (0.5mb) in file size and no larger than 1024x768 pixels. Photographs can be resized using editing software such as Microsoft Office Picture Manager and Photoshop, or free downloads such as Google’s Picasa.