diff --git a/10 - Hold Shift and Check Checkboxes/index-START.html b/10 - Hold Shift and Check Checkboxes/index-START.html
index aeac48e7f9..84b40075a9 100644
--- a/10 - Hold Shift and Check Checkboxes/index-START.html	
+++ b/10 - Hold Shift and Check Checkboxes/index-START.html	
@@ -98,7 +98,6 @@
     </div>
   </div>
 
-<script>
-</script>
+<script src="script.js"></script>
 </body>
 </html>
diff --git a/10 - Hold Shift and Check Checkboxes/script.js b/10 - Hold Shift and Check Checkboxes/script.js
new file mode 100644
index 0000000000..8b078bf94b
--- /dev/null
+++ b/10 - Hold Shift and Check Checkboxes/script.js	
@@ -0,0 +1,20 @@
+let isShwifty = false;
+let lastChecked;
+
+const doTheThing = (e) => {
+  let inBetween = false;
+  if (e.shiftKey && e.target.checked) {
+    checkBoxes.forEach(checkbox => {
+     if (checkbox === e.target || checkbox === lastChecked) {
+       inBetween = !inBetween;
+     } 
+      if (inBetween) {
+        checkbox.checked = 'true';
+      }
+    });
+  }
+  lastChecked = e.target;
+};
+
+const checkBoxes = document.querySelectorAll('.item input[type="checkbox"]');
+checkBoxes.forEach(box => box.addEventListener('click', doTheThing));