title: Why does a FORM with one text INPUT submit on enter while one with two text INPUTs does not?
body: <p>I have just found out that a FORM containing only one INPUT (not hidden) will automatically submit when pressing Enter.</p>
  
  <p>But a form containing at least two INPUTS (not hidden) will NOT submit when pressing enter.</p>
  
  <p>(None of the scripts have a submit/button/input[type=submit] inside)</p>
  
  <p>Take a look at this <a href="http://jsfiddle.net/RV6cW/">jsfidle</a>. Is there an explanation/standard for this behavior?</p>
  
  <pre><code>&lt;form id="form1" method="POST"&gt;
      &lt;p&gt;Does submit:&lt;/p&gt;
      &lt;input type="text" placeholder="focus and press enter"/&gt;
  &lt;/form&gt;
  
  &lt;form id="form2" method="POST"&gt;
      &lt;p&gt;Does &lt;strong&gt;not&lt;/strong&gt; submit:&lt;/p&gt;
      &lt;input type="text" placeholder="does not submit"/&gt;
      &lt;input type="text" placeholder=""/&gt;
  &lt;/form&gt;
  </code></pre>