ToolbarSets without modifying fckconfig.js

Hi,

I'm trying to add custom ToolbarSet on the page without modifying the fckconfig.js but FCK says that such a tollbar set is not found.

   this.create=function(){
      editor = new FCKeditor(editorId);
      editor.BasePath = "../Content/fckeditor/" ;
      editor.Height = "500px";      
      editor.Config.ToolbarSets = {};
      editor.Config.ToolbarSets["Custom"] = [
         ['Bold','Italic','Underline','StrikeThrough','-','Subscript','Superscript']
      ];
      editor.ToolbarSet = "Custom";
      
      editor.ReplaceTextarea();
   };

What's the correct way of doing it?

Thanks,
Dmitriy.