// get user input
                            function getValue() {
                                // hide alert
                                document.getElementById('alert').classList.add('invisible');
                            
                                // Get the string from the page
                                let userString = document.getElementById('userString').value;
                            
                                // check for palindrome
                                let retObject = checkForPalindrom(userString);
                            
                                displayString(retObject);
                            }
                            
                            // Reverse the string
                            function checkForPalindrom(userString) {
                                let revString = [];
                                let retObject = {};
                            
                                // remove spaces and special characters
                                let regEx = /[^A-Za-z0-9]/gi;
                                userString = userString.replace(regEx, '');
                            
                                // reverse string using a for loop
                                for (let i = userString.length - 1; i >= 0; i--) {
                                    revString += userString[i];
                                }
                            
                                // fill object
                                if (userString.toLowerCase() == revString.toLowerCase()) {
                                    retObject.title = 'Well done! You entered a palindrome.';
                                } else {
                                    retObject.title = 'Sorry! You did not enter a palindrome.';
                                }
                            
                                retObject.reversed = revString;
                            
                                return retObject;
                            }
                            
                            // Display the palindrome string to the user
                            function displayString(retObject) {
                                document.querySelector('#alertTitle').innerHTML = retObject.title;
                                document.getElementById('msg').innerHTML = `Your phrase reversed is: ${retObject.reversed}`;
                                document.getElementById('alert').classList.remove('invisible');
                            }
                            
                        

The Code is structured in several functions.

getValue

Gets the user input string

checkForPalindrom

Remove all characters except for letters and numbers of user input string. Then reverse the remaining characters into another variable. Finally, compare the two variables to verify if palindrome or not.

displayString

Displays the result to user in an alert box.