When a dialog is presented, a translucent black underlay is created to
provide prominence to the dialog.

When screenshots of dialogs are made for documentation, the underlay
provides an undesirable dark border around the dialog.

The following bookmarklet locates the underlay and makes it opaque
white so that dialog screenshots will present nicely in documentation.

javascript:var%20underlay%20=%20dojo.query(%27.dijitDialogUnderlayWrapper%20.dijitDialogUnderlay%27)[0];if%20(underlay)%20{dojo.style(underlay,%20{%20background:%20%27white%27,%20opacity:%201%20});}