Automaticly Resize pictures?

When I post a Image on my forum it is automaticly cut in half and the other half doesn't appear unless I right click and choose view image.
What can I do To change it?
Thanks!

Here is a link to a thread that has this problem (its through out the forum)
Click

You can use the image hosting called photobucket.com or serving.com and click the right size you want to.

It's a problem that has been mentioned many times
solutions are either reduce the size of the picture to
suit or use PHPBB2 forum board, as other forum boards
wont scroll horizontaly............

Ohh Ok, So what your saying is that there isn't a setting that I can change to fix this correct?

and the only way is to resize the image beforehand?

Just trying to confirm.