Tidying it a bit.

public/index.html

@@ -80,65 +80,54 @@
           $(this).attr('src'));
       });
 
-      // the counter variable that keeps
-      // track of which image you are showing
+      // The counter variable that keeps track of which image you are showing.
       var counter = 1;
 
-      // virtually click on the current
-      // image to load it into the big image
+      // Virtually click on the current image to load it into the big image.
       $("#image" + counter).click();
 
-      // when you click on the backwards
-      // button select the previous image
+      // When you click on the backwards button select the previous image
       $("#backward").click(function () {
-        // go back one in the counter
-        counter = counter - 1;
-        // if we are below 1 (the first
-        // image) loop round to 4 (the
-        // last image)
+        // Go back one in the counter.
+        counter--;
+
+        // If we are below 1 (the first image) loop round to 4 (the last image).
         if (counter < 1) {
           counter = 4;
         }
-        // virtually click on the current
-        // image to load it into the big image
+
+        // Virtually click on the current image to load it into the big image.
         $("#image" + counter).click();
       });
 
-      // when you click on the backwards
-      // button select the next image
+      // When you click on the backwards button select the next image.
       $("#forward").click(function () {
-        // go forward one in the counter
-        counter = counter + 1;
-        // if we are above 4 (the last
-        // image) loop round to 1 (the
-        // first image)
+        // Go forward one in the counter.
+        counter++;
+
+        // If we are above 4 (the last image) loop round to 1 (the first image).
         if (counter > 4) {
           counter = 1;
         }
-        // virtually click on the current
-        // image to load it into the big image
+
+        // Virtually click on the current image to load it into the big image.
         $("#image" + counter).click();
       });
 
-      // when you click the big image
-      // toggle pausing. Set paused to
-      // not paused, i.e. if it is paused
-      // set it to not paused, if it is
-      // not paused set it to paused
+      // When you click the big image toggle pausing. Set paused to not paused,
+      // i.e. if it is paused set it to not paused, if it is not paused set it
+      // to paused.
       $("#bigImage").click(function () {
         paused = !paused;
       });
 
-      // set interval makes it move
-      // forward every 3 second
+      // Set interval makes it move forward every 3 second.
       setInterval(function () {
-        // first check if it is paused
+        // First check if it is paused.
         if (!paused) {
-          // virtual click the forward
-          // button
+          // Virtual click the forward button.
           $("#forward").click();
         }
-        ;
       }, 3000);
     </script>
   </body>