diff --git a/index.html b/index.html
index 65f13c3..e3711d7 100644
--- a/index.html
+++ b/index.html
@@ -94,23 +94,39 @@
 <html>
 <script>
   function toggleSections(button){
+    // Constants 
     hiddenClass = "hidden";
     revealedClass = "visible";
+    ids = ["about", "projects", "contact"];
+    selectedClasses = ["border-[#14591e]" , "border-b-2"]
+    // Helper functions
     function switchClasses(element, toRemove, toInsert){
       element.classList.remove(toRemove);
       element.classList.add(toInsert);
     }
+    function removeClasses(element, classes){
+      element.classList.forEach()
+    }
     function hide(id) {
       switchClasses(document.getElementById(id), revealedClass, hiddenClass);
     }
     function show(id) {
       switchClasses(document.getElementById(id), hiddenClass, revealedClass);
     }
+    function hasClasses(element, classes){
+      return classes.map(c => element.classList.contains(c)).reduce((acc, b) => acc && b, true);
+    }
+    // Handle underline for tab buttons
+    parent = button.parentElement;
+    // Remove selection classes from other buttons 
+    // If button clicked already selected, unselect
+    // Otherwise select 
+
+    // Manage hiding/showing content
     id = button.textContent;
-    ids = ["about", "projects", "contact"];
     ids.filter(i => i !== id).forEach(hide);
     element = document.getElementById(id);
-    if(element.classList.contains(revealedClass)){
+    if(hasClasses(element, [revealedClass])){
       switchClasses(element, revealedClass, hiddenClass);
       return;
     }
