samer@0: function acquire(a)
samer@0: 	ud=get(0,'UserData');
samer@0: 	i=find(ud.figs==fig(a));
samer@0: 	if isempty(i)
samer@0: 		ud.figs=[ud.figs, fig(a)];
samer@0: 		ud.arrows=[ud.arrows,{a}];
samer@0: 		set(0,'UserData',ud);
samer@0: 	else
samer@3: 		fprintf('Arrow %s [%s] cannot use figure %d, already in use by %s [%s].\n',...
samer@3: 			tostring(a),a.opts.name,fig(a),tostring(ud.arrows{i}),ud.arrows{i}.opts.name);
samer@0: 		error('Figure already in use by arrow.');
samer@0: 	end
samer@0: end