Mike ;
On the "post reply" screen , at the bottom you'll see an option "upload attachment"
Where it says "filename" , use the "browse" option to search for the relevent pic on your computer , then click on "open" , then click on "add the file".
Towards the bottom of the screen , you will now get another menu open up , "posted attachments".
Click on the "place inline" option & it will add the picture into your message.
You can do this for up to 3 images per posting.
Bear in mind , though ,that the maximum file size it will accept is 256kb { 800x600 should be ok , you may get up to 1024x600-ish }
Let me know if this works OK.