The picture has to be on the WWW and not on your computer. you then use the add picture icon and enter the address where the picture is stored
For example if you RIGHT CLICK on the accringtoweb logo at the top of this page and select PROPERTIES it shows you the address of the picture ie .. Simply cut and paste that.
If your picture isn't on the WWW and is on your computer then thats a whole differnt kettle of fish which requires a lot more explaining