code: function() {
  			var el = this.parts.dialog;
  			var dialogSize = this.getSize();
  			var win = CKEDITOR.document.getWindow(),
  					viewSize = win.getViewPaneSize();
  
  			var posX = ( viewSize.width - dialogSize.width ) / 2,
  				posY = ( viewSize.height - dialogSize.height ) / 2;
  
  			// Switch to absolute position when viewport is smaller than dialog size.
  			if ( !CKEDITOR.env.ie6Compat ) {
  				if ( dialogSize.height + ( posY > 0 ? posY : 0 ) > viewSize.height ||
  						 dialogSize.width + ( posX > 0 ? posX : 0 ) > viewSize.width )
  					el.setStyle( 'position', 'absolute' );
  				else
  					el.setStyle( 'position', 'fixed' );
  			}
  
  			this.move( this._.moved ? this._.position.x : posX,
  					this._.moved ? this._.position.y : posY );
  		}
docs: Rearrange the dialog to its previous position or the middle of the window.
  
  @since 3.5