Okay... yes i just had this problem like two days ago. But my brother told me how to do it. Right click on the picture that you want to put in. Then go to properties.. then click on the URL, and type Ctrl A to select it. (it should be a .jpg address.) then copy it (Ctrl C) and put it in this box that I am typing in at the moment. But it has to be in this code.
that should work... but it has to be in .jpg form (the address that is) or it wont work.