function help2_callback
DI=dialog('unit','normalized','position',[.34 .2 .35 .6],'name','Help');

AI=axes('parent',DI,'visible','off');
t={ '\fontname{Times New Romman}\fontsize{9}The  file  fZk.mat  where the  simulated ',... 
    ''...
    'mesurements (in the form of a cell array ',...
    ''...
    'Zk)  are stored  is created  according to  ',...
    '',...
    'the model specified at the time the filter  ',...
    '',...
    'is  initialized.  You  can  use  ''Generate',...
    '',...
    ' Mesurements'' to create the file fZk.mat ',...
    '',...
    'after the filter is initialized.'};
    

text(0,.6,t,'parent',AI);


uiwait(DI);%suspend the other programmes.