I'm pretty much a forum/Mac rookie so bear with me. I am trying to create a signature with a photo and can't figure out how to do it. I click on the "insert image" icon and it asks me for the URL of my image, which i don't know. I try dragging the photo into the signature area (when I am in the signature editor) and all it shows is the location of the pic on my computer. What am I missing here?