Here's what you do. If the pic is already on the web and you are using internet explorer as a browser, simply right click on the image, then select "properties" on the menu that pops up. This will give you the image location:
Then just copy the part before the "http://" and place in between [chart ] and [ /chart] .....with no spaces between the [ and chart. I had to put in the spaces so they would show up.
The image above looks like this when done, but with no spacing: