Question

using Documentation on IIS;

<?php 
    $key = '**********';
    $value = '**********';
    session_start ( );

    $code = $_REQUEST [ 'code' ];
    if ( empty ( $code ) )
    {
        $_SESSION [ 'state' ] = md5 ( uniqid ( rand ( ) , true ) );
        $dialog_url = 'https://www.facebook.com/dialog/oauth?client_id=' . $key . '&redirect_uri=' . urlencode ( $value ) . '&state=' . $_SESSION [ 'state' ];
        echo('<script> top.location.href=' . $dialog_url . ';</script>');
    }
?>

Result:

top.location.href=' . $dialog_url . ';'); } ?> 

Please try your suggestion before posting it as I have tried more than 40 suggestions, reviewed all similar questions and searched it for last 2 hours.

Answer 1

Your server do not parse your file as php. That’s the symptom.

See how to configure your IIS server for parse html file as PHP.

EDIT for completeness:

As mentioned by other answers you should add double quotes around $dialog_url for prevent javascript error

echo('<script> top.location.href="' . $dialog_url . '";</script>');