title: Why variable that declared in a using statement treated as readonly?
body: <p>why variable (myform) in using block treated as read-only and the compiler raise an error when I try to pass it as a reference to a function.</p>
  <p>sample code:</p>
  <pre><code>using (Form myform = new Form)
  {
      myfunc(ref myform);
  }
  </code></pre>
  <p>passing using variable to a function as ref will raise an error. thus the code above will raise an error.</p>
  <p><strong>Note</strong> : 'readonly' keyword is unrelated to my question.</p>