title: Unique HTML IDs on a page
body: <p>I often had the following on a form:</p>
  
  <pre><code>input#userid{
      left : 10px;
      top:130px;
      width : 180px;
  }
  
  label#userid{
      left : 10px;
      top:156px;
  }
  </code></pre>
  
  <p>I am aware that ids on a page should be unique and have always considered the above to be unique.  Now however I am reading about "label for" and wonder if my IDs are truly unique in the spirit of HTML.</p>