title: Check when input type text is filled
body: <p>I have a form with input types text. Like this:</p>
  
  <pre><code>&lt;input type="text" placeholder="Voornaam" class="required" title="Voornaam" id="ctl00_ContentPlaceHolder1_tbFirstName" maxlength="255" value="Mike" name="ctl00$ContentPlaceHolder1$tbFirstName"&gt;
  </code></pre>
  
  <p>But now my question. Normally the text is gray in the text fields. But when you have completed a field. The color must be black. How can i check this with javascript? </p>
  
  <p>Thanks</p>