@code{mouse-drag-region}, then the @code{REGION} section will be
enabled.
-In addition, @code{REGIONTEXT} will be set the the text in the region,
+In addition, @code{REGIONTEXT} will be set to the text in the region,
and that region of text will be ``killed'' from the current buffer.
If standard-output is NOT the current buffer, then the region will not