Fatal error: Class 'FCKeditor' not found

<?php
require("http://www.test.com/777/FCKeditor/fckeditor_php5.php");
$oFCKeditor = new FCKeditor('text'); //This is line 55: 
$oFCKeditor->BasePath = '/777/FCKeditor/' ;
$oFCKeditor->Width  = '550' ;
$oFCKeditor->Height = '600' ;
$oFCKeditor->ToolbarSet = 'Default';
$oFCKeditor->Value = ''.$text.'';
$oFCKeditor->Create();
?>