The Code

function getValues(){
    // Grab the user's input
    let messageInput = document.getElementById("message").value;
    // Select the alertMessage div from the HTML
    let alertMessage = document.getElementById("alertMessage");
    // Set the display message and then display it, calling the
    // rewind function in the process
    let outputMessage = displayMessage(messageInput, rewind(messageInput));
    alertMessage.innerHTML = outputMessage;

}
function rewind(string) {
    // Function to rewind the string
    let rewound = "";
    for (let i = string.length - 1; i >= 0; i--) {
        // Iterate backwards over the user's string
        rewound += string[i];
        // Build out the reversed string one
        // character at a time
    }
    return rewound;
    // Return the reversed string
}
function displayMessage(input, output) {
    // Take the user's input and the
    // applet's output and display them
    document.getElementById("alertMessage").style.opacity = 1;
    // Make the alert box visible
    let message = `<div>Your message, <i>${input}</i> reversed is <i>${output}</i></div>`
    // Build out the HTML to be displayed
    return message;
    // Give the HTML back to the original function
}