Okay, take the link that appears after you get to the page that reads
upload successful (I am assuming you got that far). Cut and paste the link that appears:
http://www.simviation.com/yabbuploads/alt+tab over to the window where you're trying to post the image, then type {img}{/img}.
Paste the
http://www.simviation.com/yabbuploads/ between the {img}{/img} tags (I have to substitute the [] brackets with {} or you won't be able to see the code, defeating the purpose of this post...
Example (with {} substituted for [])
{img}http://www.simviation.com/yabbuploads/{img}
Now all that's missing is the name of your file...I use explorer, and copy the name by hitting F2 over the highlighted file and then hit ctrl+c. I also pick complicated names so that they are less likely to be overwritten by subsequent uploads...
For example lets say I wanted to show a picture called
5ThrwOffYksjj.jpgI would paste it
here...
{img}http://www.simviation.com/yabbuploads/
5ThrwOffYksjj.jpg{img}
Annd changing the {} to [] (removing the bold tags as well) we get:

Remeber that the name has to be
exactly the same as it is on your hard drive (it's case-sensitive too).
You can also look at the code by hitting the quote tag in the forum, that will also show you the correct code syntax...
Happy posting
