Upload problem

Hello,
I'm trying to use upload fonction. But It does't work.
I've made the following things :

- I'm use fckeditor 2 with spip.
- 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" ;

I don't know if I must change this variable
FCKConfig.LinkUploadURL ...

But anyway, when I try to use the upload browser to create a directory, I have a javascript alert which said :"You have no permission to create the folder".

So I've got forgotten something ?

Thanks for your help.
Best Regards