diff --git a/index.html b/index.html
index 22c76f5..c012732 100644
--- a/index.html
+++ b/index.html
@@ -117,8 +117,13 @@ <h2 class="text-white mb-4">DDD Filter applications in the Network</h2>
 
                   <script>
                     function openNav() {
-                      document.getElementById("mySidebar").style.height = "250px";
-                      document.getElementById("main").style.marginTop = "250px";
+                      if(document.getElementById("mySidebar").style.height == "250px"){
+                        closeNav();
+                      }
+                      else{
+                        document.getElementById("mySidebar").style.height = "250px";
+                        document.getElementById("main").style.marginTop = "250px";
+                      }
                     }
 
                     function closeNav() {