MATLAB: Value from popup for a another calculation

matlab gui

function popupmenu3_Callback(hObject, eventdata, handles)
 contents = cellstr(get(hObject,'String')); 
 Werkstoff= contents{get(hObject,'Value')};
  if(strcmp(Werkstoff,'C25'))
    Rm_N= 550; %MPa
    Rp_N=600;
  elseif(strcmp(Werkstoff,'C40'))
      Rm_N=600;
      Rp_N=800;
  elseif(strcmp(Werkstoff,'C45'))
      Rm_N=100;
      Rp_N=5500;
  end
I Choose one option from the popup and then i get values for Rm_N and Rp_N. What i need to do, when I want to use the Rm_N and Rp_N from my chosen option for my calculation in the bottom?
function pushbutton1_Callback(hObject, eventdata, handles)
% Zug-Druck
S_max_zd= *Rp_N*;
F_Max_zo= *Rm_N*/2;
set(handles.text39, 'string', S_max_zd);
set(handles.text40, 'string', F_max_zo);
Related Question