function clearzrange
%CLEARZRANGE Clear the Z range values.

%
% Copyright (c) 1995 by Claudio Rivetti and Mark Young
% claudio@alice.uoregon.edu,    mark@alice.uoregon.edu
%

global ed_zrange1 ed_zrange2 Handlebar

tx=get(Handlebar, 'Userdata');
set(tx, 'string', '');
set(ed_zrange1, 'string', '');
set(ed_zrange2, 'string', '');

return