function g_pzmodelGainEdit(hObject, varargin)
   
   global params
   
   currParamIndex = get(hObject,'UserData');
   pzGain         = str2double(get(hObject,'String'));
   pzObj        = params.params(currParamIndex);
   pzKey        = pzObj.key;
   pzObj        = pzObj.val;
   pzObj      = pzmodel(pzGain,pzObj.poles,pzObj.zeros);
   params    = pset(params,pzKey,pzObj);
   set(findobj('Tag','apply'),'Enable','on');
   set(findobj('Tag','undo'),'Enable','on');
   
end