Above the dialog box on the reply page there are two buttons, one has a picture of a floppy disk with a polaroid behind it, the one next to it has just a polaroid on it. Click the one with the disk to upload a picture from your computer, click the other to link from an image host. Just follow the directions and you should do fine, might take a couple attempts the first time though. The goal is to copy an image "url" into your message. The one will create one for the pictures in yor computer. Good luck.