ments
are all of the windows grabbed by this application for all displays,
or an empty string if the application has no grabs.
<P><DT><A NAME="M7"><B>grab release </B><I>window</I></A><DD>
Releases the grab on <I>window</I> if there is one, otherwise does
nothing.  Returns an empty string.
<P><DT><A NAME="M8"><B>grab set </B>?<B>-global</B>? <I>window</I></A><DD>
Sets a grab on <I>window</I>.  If <B>-global</B> is specified then the
grab is global, otherwise it is local.
If a grab was already in effect for 