(function redBoxButton() { // Create a new div element var newDiv = document.createElement("div"); // Set the id attribute of the new div newDiv.id = "aspect-ratio-helper"; // Create a nested div inside the new div var nestedDiv = document.createElement("div"); // Append the nested div to the new div newDiv.appendChild(nestedDiv, newDiv.firstChild); // Get the parent element where you want to append the new div var parentElement = document.body; // Change this to your desired parent element // Append the new div to the parent element parentElement.insertBefore(newDiv, parentElement.firstChild); // Create the button element var hideShowButton = document.createElement("button"); hideShowButton.innerHTML = ''; hideShowButton.className = "icon-button"; hideShowButton.type = "button"; hideShowButton.title = "Outline the area that fits on one screen while teaching the course."; hideShowButton.id = "Dev"; var navbarButtons = document.getElementsByClassName("left-buttons"); navbarButtons[0].insertBefore(hideShowButton, navbarButtons.firstChild); //Default hiding the redbox document.getElementById("aspect-ratio-helper").style.display = "none"; //Add Event listener to button to perform on click action. hideShowButton.addEventListener("click", function () { if ( document.getElementById("aspect-ratio-helper").style.display === "none" ) { document.getElementById("aspect-ratio-helper").style.display = "block"; hideShowButton.innerHTML = ''; } else { document.getElementById("aspect-ratio-helper").style.display = "none"; hideShowButton.innerHTML = ''; } }); })();