use php fusion authentication for external page

If that is a PHP File, then you can Try this :

[syntaxhighlighter brush=php,first-line=1,highlight=0,collapse=false,html-script=false]require_once "maincore.php";

if (iMEMBER)
{
echo "The Code which you want to show, if the User if Logged In : For Example :- \n";
echo "<br />The User is Logged In";
}
else
{
echo "The Code you want to show if Not Log In, say Error !!! \n";
echo "<br />The User is Not Logged In ! Access Denied !";
}
[/syntaxhighlighter]

Not work

message said :
Not Found
The requested URL /upload/setup.php was not found on this server.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

Could you please provide more details about your files ? Please also give your site Link where you are testing ...

Do you have PHP Fusion installed ? If yes, then where is the File located in which you are doing this change ?

I mean that this script may work if you will place the file in the same Directory where PHP Fusion files are saved,i.e, root directory...

Please show us a link to your website. I've got information that someone with your nick owns a website where the copyrights are removed.

I test it locally , PHP fusion already installed in :
www.localhost.com/mag/

and the PHP file located in :
www.localhost.com/mag/upload/index.php

So the Php file loacted inside PHP fusion dir

replace

to

I already change the dir "../maincore.php" but still not work , it's redirect me to setup.php !!!!

You have to upload the Files and folders into the root of your site... If the Site URL is something ...yoursite.com/folder/ then php files should be in the folder folder...