The best way to do this is to ignore that option image URL line Mark. If the link is preceded with http etc, the forum will recognise it as a link and you can include it right in the middle http://www.baynuts.com.au/home.html of your post as inline text.

I ignore that URL line for images too, though it is best to let these break to a new line to save messing up all the formatting. The image just needs to be bracketed with the image flags and it will show up as such.