function legend_callback

try    
 T=findobj(gcf,'tag','compo1');
 co=get(T,'userdata');
 s=num2str(co(1));
catch
    return
end

s=['''',s,''''];
for i=2:length(co)
    s=[s,',','''',num2str(co(i)),''''];
end
  
try
  L=findobj(gcf,'tag','legendh');%%%%
  switch get(L,'userdata')          % 
  case 1,                           %
     set(L,'userdata',0);           %naming legendh to avoid collision with eval...
     legend off                     %
  case 0,                           %
     eval(['legend(',s,')']);%%%%%%%%    
     set(L,'userdata',1);
  end
catch
    return
end