text: function search_google(q, isbn){
  
    var query = "";
    if(q != ""){
      query += q;
    } else if(isbn != ""){
      query += "isbn:"+isbn;
    }
  
    var url = "https://www.googleapis.com/books/v1/volumes?q="+query+"&format=json";
  
    show_url(url);
  
    $.getJSON(url, function(data) {
  
      console.log(data);
  
      var items = data["items"];
      for(var i = 0; i < items.length; i++){
        var item = items[i]["volumeInfo"];
        var title = item["title"];
        var publisher = item["publisher"];
        var url = item["infoLink"];
        var thumb = null;
        if(item["imageLinks"]){
          thumb = item["imageLinks"]["smallThumbnail"];
        }
        add_row(thumb, title, publisher, url);
      }
    })
  }
  