figure
figure
figure(1)
F1 = uicontrol('pos',[.12 .86 .82 .10],'style','edit','horiz','left', ...
    'string', [blanks f1],'call','f1 = get(F1,''string''); 
imtext(.07,.79,'f2 = ','left');
figure(2)
ezplot(f1,x,1)





F1 = uicontrol('pos',[.12 .86 .82 .10],'style','edit','horiz','left', ...
    'string', [blanks f1],'call','f1 = get(F1,''string'');');

works:

 F2 = uicontrol('style','edit','horiz','right', ...
 'string', [blanks f1],  'call' ,'f2 = get(F2,''string'')');
%  outputs the string immediately

 F1 = uicontrol('style','edit','horiz','left', ...
    'string', [blanks f1],'call','f1 = get(F1,''string'');');