execute only if element is on page

js/burgerMenu.js

-document.querySelector("#burgerMenu").onclick = () => {
+let burgerMenu = document.querySelector("#burgerMenu");
+
+if(burgerMenu != null) {
+    burgerMenu.onclick = () => {
         document.getElementById("burgerMenu").classList.toggle("change");
         document.getElementById("mainMenuContainer").classList.toggle("visible");
 
     }
+}
\ No newline at end of file

js/cookie.js

@@ -10,7 +10,9 @@ function getCookie(name){
     return null
 }
 
+
 let cookieInfo = document.querySelector(".cookieinfo");
+if(cookieInfo != null) {
     if (getCookie("cookieMessageHide") === "1") {
         cookieInfo.style.display = "none";
     } else {
@@ -22,3 +24,5 @@ document.querySelector(".cookieinfo-close").onclick = function() {
         document.cookie = "cookieMessageHide=1";
         cookieInfo.style.display = "none";
     }
+
+}
\ No newline at end of file