You have no permission to create the folder

Hello,
somebody already have this javascript alert in trying to create a folder ?

I create a 'UserFiles' directory to the root of kfceditor directory
-I put a chmod 777 permissions for the 'UserFiles' directory and his dpendances (subfolder).
-I configurate ImageBrowserURL and LinkBrowserURL like this :

 
FCKConfig.LinkBrowserURL = FCKConfig.BasePath + "filemanager/browser/default/browser.html?Connector=connectors/php/connector.php" ; 
FCKConfig.LinkBrowserWindowWidth = screen.width * 0.7 ; // 70% 
FCKConfig.LinkBrowserWindowHeight = screen.height * 0.7 ; // 70% 
 
// Link Upload 
FCKConfig.LinkUpload = true ; 
FCKConfig.LinkUploadURL = FCKConfig.BasePath + "filemanager/upload/aspx/upload.aspx" ; 
FCKConfig.LinkUploadWindowWidth = 300 ; 
FCKConfig.LinkUploadWindowHeight = 150 ; 
FCKConfig.LinkUploadAllowedExtensions = "*" ; // * or empty for all 
FCKConfig.LinkUploadDeniedExtensions = ".exe .asp .php .aspx .js .cfm .dll" ; // empty for none 
 
// Image Browsing 
FCKConfig.ImageBrowser = true ; 
//FCKConfig.ImageBrowserURL = FCKConfig.BasePath + "filemanager/browser/default/browser.html?Type=Image&Connector=connectors/asp/connector.php" ; 
//FCKConfig.ImageBrowserURL = FCKConfig.BasePath + "filemanager/browser/default/browser.html?Type=Image&Connector=connectors/aspx/connector.aspx" ; 
FCKConfig.ImageBrowserURL = FCKConfig.BasePath + "filemanager/browser/default/browser.html?Type=Image&Connector=connectors/php/connector.php" ;