Functions calling back function

The followwing code should shows the value of "a" when the user press the submenue "ADD or "MULT". but it does not. Why?

if true

     function mygui5c
        %creating the figure
         f = figure('visible','on','Position',[350,100,650,500],'color', [0.25,0.83,0.83]);
            i_menu = uimenu('Label','My Menu');
         op1_menu = uimenu(i_menu,'Label','ADD','callback',{@op1_callback});
         op2_menu = uimenu(i_menu,'Label','MULT','callback',{@op2_callback});
          global c
  global a
  c = 0;

if c ==1
    a = 10
elseif c ==2
    a = 100
end

      function op1_callback(hObject,eventdata)
          c =1;
          mygui5c
      end
      function op2_callback(hObject,eventdata)
          c=2;
      end
  end

    end

Answer 1

[Andrew Reibold]

Because you set c to zero right before your if/else statements.

c = 0;

Then you say "If c equals 1, then a = 10"

if c ==1
  a = 10

This is not true, because c = 0.

And then you say "If thats not true, but c equals 2, then a=100"

elseif c ==2
  a = 100

This is also not true, because c does not equal 2... c = 0. You don't have any more 'else' statements so nothing happens and 'a' is never set.