text: /*Name this external file gallery.js*/
  
  function upDate(previewPic){
  
    document.getElementById('image').innerHTML = previewPic.alt;
   document.getElementById('image').style.backgroundImage="url" + "("+ previewPic.src + ")";
   
      }
  
      function unDo(){
          
      document.getElementById('image').innerHTML='Hover over an image';
      document.getElementById('image').style.backgroundImage='none';
      
       /* In this function you should 
      1) Update the url for the background image of the div with the id = "image" 
      back to the orginal-image.  You can use the css code to see what that original URL was
      
      2) Change the text  of the div with the id = "image" 
      back to the original text.  You can use the html code to see what that original text was
      */
          
      }