title: PHP my checking in the if statement to re-populate a checked button is not working
body: <p>I recently found out how to re-populate checked radio buttons.. but Im not sure why right now its jumping to re-populate the last one of them even if the checked is the first one. 
  I can't find my mistake, I hope some can.. Thanks lots..</p>
  
  <pre><code> &lt;tr&gt;
          &lt;td class="right text"&gt;Title:&lt;/td&gt;
          &lt;td&gt;&lt;input type="radio" name="sex" value="Mr." &lt;?php if (isset($_POST['sex']) == "Mr.") echo "checked"; ?&gt;&gt;Mr.&lt;/td&gt;&lt;/tr&gt;
      &lt;tr&gt;&lt;td&gt;&lt;/td&gt;&lt;td&gt;&lt;input type="radio" name="sex" value="Mrs." &lt;?php if (isset($_POST['sex']) == "Mrs.") echo "checked"; ?&gt;&gt;Mrs.&lt;/td&gt;&lt;/tr&gt;
      &lt;tr&gt;&lt;td&gt;&lt;/td&gt;&lt;td&gt;&lt;input type="radio" name="sex" value="Ms." &lt;?php if (isset($_POST['sex']) == "Ms.") echo "checked"; ?&gt;&gt;Ms.&lt;/td&gt;&lt;/tr&gt;
  </code></pre>