To display an image on your posts, first click on "Add File" button then you have to click on "Insert" button. It will add a code in the Message Text area (example [ attachement:000 ]filename.jpg[ attachement]). In the example I added spaces after and before the brackets so the code is not interpreted but it should not have spaces.
You can place this code where you want to make appear the image in your text.
Display an image on your posts 
