Custom 404 error page

I searched it via google and found some article tutorial how to create a custom 404 error page. But It forces me to use a specific link as the error page for example notfound.html. What I want is If you go on a not found page It stays on the page but shows my custom error page.
Here's an example:
http://www.flyffworld.com/456

 

No one knows about to do this?

 

The Method will vary depending on server setup, I noticed port 2082 is open on the server hosting the site in your sigs so I will assume its running cpanel.

create a html error page and copy the code into the this section of your cpanel

http://yourdomainnamehere.com:2082/frontend/x/err/index.html if you are running x3 theme etc just change that part of the url as needed

This will create a 404.shtml file in your public_html directory that can be edited whenever

Hope this helps

 

httpd ( Apache config file ) :

# 404 Error
ErrorDocument 404 /apache_error/404.html

Code (markup):

Once you've created your custom .html file, restart & enjoy

 

Assuming they have root access it'll work

 

Assuming they want to create such a "feature" .. they have root access