code: function( dialogName, callback ) {
  			var dialog = null, dialogDefinitions = CKEDITOR.dialog._.dialogDefinitions[ dialogName ];
  
  			if ( CKEDITOR.dialog._.currentTop === null )
  				showCover( this );
  
  			// If the dialogDefinition is already loaded, open it immediately.
  			if ( typeof dialogDefinitions == 'function' ) {
  				var storedDialogs = this._.storedDialogs || ( this._.storedDialogs = {} );
  
  				dialog = storedDialogs[ dialogName ] || ( storedDialogs[ dialogName ] = new CKEDITOR.dialog( this, dialogName ) );
  
  				callback && callback.call( dialog, dialog );
  				dialog.show();
  
  			} else if ( dialogDefinitions == 'failed' ) {
  				hideCover( this );
  				throw new Error( '[CKEDITOR.dialog.openDialog] Dialog "' + dialogName + '" failed when loading definition.' );
  			} else if ( typeof dialogDefinitions == 'string' ) {
  
  				CKEDITOR.scriptLoader.load( CKEDITOR.getUrl( dialogDefinitions ),
  					function() {
  						var dialogDefinition = CKEDITOR.dialog._.dialogDefinitions[ dialogName ];
  						// In case of plugin error, mark it as loading failed.
  						if ( typeof dialogDefinition != 'function' )
  							CKEDITOR.dialog._.dialogDefinitions[ dialogName ] = 'failed';
  
  						this.openDialog( dialogName, callback );
  					}, this, 0, 1 );
  			}
  
  			CKEDITOR.skin.loadPart( 'dialog' );
  
  			return dialog;
  		}
docs: Loads and opens a registered dialog.
  
  CKEDITOR.instances.editor1.openDialog( 'smiley' );
  
  @member CKEDITOR.editor
  @param {String} dialogName The registered name of the dialog.
  @param {Function} callback The function to be invoked after dialog instance created.
  @returns {CKEDITOR.dialog} The dialog object corresponding to the dialog displayed.
  `null` if the dialog name is not registered.
  @see CKEDITOR.dialog#add