title: How to fix this CSS validation error..?
body: <pre><code>.file_input_hidden {
      font-size: 45px; 
      position: absolute; 
      right: 0px; 
      top: 0px; 
      filter: alpha(opacity=0); 
      -ms-filter: "alpha(opacity=0)";
      -khtml-opacity: 0; 
      -moz-opacity: 0;
      opacity: 0;
  } 
  </code></pre>
  
  <p>This is the code. When i run it in sortsite, CSS validation error is shown 6th line of the code (top: 0px;). 
  I could not trace out the issue.
  Is there any thing wrong in filters?
  Please help me out in fixing this issue.</p>