title: What is the difference between readonly="true" & readonly="readonly"?
body: <p>What is the difference between: </p>
  
  <pre><code>&lt;input name="TextBox1" type="text" id="TextBox1" readonly="true" /&gt;
  </code></pre>
  
  <p>and:</p>
  
  <pre><code>&lt;input name="TextBox1" type="text" id="TextBox1" readonly="readonly" /&gt;
  </code></pre>
  
  <p>When i set <code>readonly</code> to <code>true</code> it works somewhat different from <code>readonly='readonly'</code>. W3C standard says <code>readonly</code> should be <code>'readonly'</code> &amp; not <code>'true'</code>. Why most of the browsers allow <code>readonly='true'</code> which has somewhat different functionality than <code>readonly='readonly'</code>?</p>