anchor.diff:  
     script.
       $(document).ready(function() {
  +      
         var uploadForm = document.getElementById('upload-form');
  -      
  -      deactivateSubmit();
  +      var uploadButton = document.getElementById('upload-button')
  +      var downloadButton = document.getElementById('download-button');
  +      var tag = document.getElementById('tag');
   
  +      deactivateUpload();
  +      deactivateDownload();
  +
  +      //- Upload button handler
         $('#file').change(function() {
           var fileVal = document.getElementById('file').value;
           if (fileVal) {
  -          activateSubmit();
  +          activateUpload();
           }
           else { 
  -          deactivateSubmit(); 
  +          deactivateUpload();
           }
         });
  +
  +      //- Download button handler
  +      tag.onkeyup = function() {
  +        var tagVal = document.getElementById('tag').value;
  +        if (tagVal.length == 0 || tagVal.length < 6) {
  +          deactivateDownload();
  +        }
  +        else {
  +          activateDownload();
  +        }
  +      }
   
         form.onsubmit = sendFile();
   
  
positive.code: //- textured maincolor
  
  extends layout
  block content
    p
  
negative.code:         return false;
        }
  
        function deactivateUpload() {
          uploadButton.disabled = true;
          uploadButton.style.opacity = 0.4;
        }
  
        function activateUpload() {
          uploadButton.disabled = false;
          uploadButton.style.opacity = 1;
        }
  
        function deactivateDownload() {
          downloadButton.disabled = true;
          downloadButton.style.opacity = 0.4;
        }
  
        function activateDownload() {
          downloadButton.disabled = false;
          downloadButton.style.opacity = 1;
        }
  
      });
  