Drupal Configuration: Error Handling

First, we modify error message for not found page. To modify it, we create a page. Click Create Content > Create Page. Enter information about error, like this:

Save it. Look node from this page. for example:

http://localhost/drupal/node/2

Then, open error reporting page by click Administer > Site Configuration > Error Reporting.

Enter page for not found page like:

Save it. Now, open not existing page such as http://localhost/drupal/node/10101010101010. You may get like this:

Repeat for access denied page