function nextPicture() {
                 // Hide current picture
                 object = document.getElementById('slide' + current);
                 object.style.display = 'none';

                 // Show next picture, if last, loop back to front
                 if (current == last) { current = 1; }
                 else { current++ }
                 object = document.getElementById('slide' + current);
                 object.style.display = 'block';
             }

             function previousPicture() {
                 // Hide current picture
                 object = document.getElementById('slide' + current);
                 object.style.display = 'none';

                 if (current == first) { current = last; }
                 else { current--; }
                 object = document.getElementById('slide' + current);
                 object.style.display = 'block';
             }
             
             // Handle multiple window onloads

             window.addOnload = function (fn) {
               if (!window.OnloadCache) window.OnloadCache = [];
                 var ol = window.OnloadCache;
                 ol.push(fn);
               }

             window.onload = function () {
               var ol = window.OnloadCache;
               if (ol)
                 for (var x = 0; x < ol.length; x++)
                 ol[x]();
               }