text: /*Name this external file gallery.js*/
  
  function upDate(previewPic){
   /* In this function you should 
      1) change the url for the background image of the div with the id = "image" 
      to the source file of the preview image
      
      2) Change the text  of the div with the id = "image" 
      to the alt text of the preview image 
      */
    
      }
  
      function unDo(){
       /* 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
      */
          
      }