First off BE CAREFUL when you use codes.   
The codes you find here are SAFE but if you do not follow the directions EXACTLY as given you could easily find it impossible to access your forum.   Be sure you follow ALL steps.      Tip:  Create a test forum where you can try out new codes, designs etc first and not worry about messing up your "real" forum.

Should you have a problem after putting in a code there are some things you can try:

1.  Disable Javascript in your browser and go to your forum.    
You "may" be able to login, edit your header and footer and correct the problem.   

To disable Javascript in Firefox: 
Tools > Options >  Content >  take checkmark out of  "enable Javascript"  in Firefox

To disable Javascript in Internet Explorer:
From the Tools menu, choose Internet Options... .
Click the Security tab.
Click Custom Level... .
Scroll to the "Scripting" section of the list. Click Disable or Enable.
Close and restart your browser.


2.  Remove your Header and/or Footer:
(This will not work in every instance...  be aware it will totally clear your header and/or Footer)

Remove Header:

http://YOUR_FORUM.smfforfreeX.com/index.php?action=style;sa=clearheader
Change YOUR_FORUM to your forum name, and the X to 2, 3 or 4. 
If you have a server 1, you will not need a number, so just remove the X.

Remove Footer:

http://YOUR_FORUM.smfforfreeX.com/index.php?action=style;sa=clearfooter
Change YOUR_FORUM to your forum name, and the X to 2, 3 or 4. 
If you have a server 1, you will not need a number, so just remove the X.

a "test forum" is just another forum.
Just sign up for a new forum.