title: what is the first step in (NSTimer release and invalidate)?
body: <p>Can I send argument with <code>@selector</code> in <code>NSTimer</code>? If I want to release <code>NSTimer</code>, are the following steps right in <code>dealloc</code>?</p>
  
  <pre><code>[timer invalidate];
  [timer release];
  </code></pre>