how big is the picture, file sizewise? if it's big like 1 mb and you don't have cable or dsl, you'll need to either resize it before attaching, or wait patiently for it to upload.
also, it will have to have the full file path name in the box, just not .jpg. needs to start out c:\ or something like that. if it's just saying .jpg, you've not double clicked on the actual picture you want attached....there needs to be that file patch, plus type of file in 2nd box.