title: Invalid operands to binary expression ('int' and 'NSString')
body: <p>I'm trying to make an Age counter, but there is an error in the first line:</p>
  
  <blockquote>
    <p>"Invalid operands to binary expression ('int' and 'NSString')"</p>
  </blockquote>
  
  <pre><code>-(IBAction)OK:(id)sender; {   
      Age = 2013 - textfield.text ;   
      label.text = [NSString stringWithFormat:@"%i" , Age];
  </code></pre>