// Get the string from the document
            // controller function
            function getValue()
            {
            
              document.getElementById("alert").classList.add("invisible");
            
              let userString = document.getElementById("userString").value;
            
              let revString = reverseString(userString);
            
              displayString(revString);
            
            }
            
            
            // Reverse it
            // logic function
            function reverseString(userString)
            {
            
              let revString = [];
            
              // reverse a string using a for-loop
              for (let i = userString.length-1; i >= 0; i--) {
                
                revString += userString[i];
                
              }
            
              return revString;
            
            }
            
            
            // Return the reversed string to the user in results
            // view function
            function displayString(revString)
            {
              // Write to the page
              document.getElementById("msg").innerHTML = `Your string reversed is: ${revString}`;
            
              // Show the alert box
              document.getElementById("alert").classList.remove("invisible");
            
            }
          
          

REWIND

The code takes in the user input and locates it through it's id. The inputted string is then looped over in reverse, and it's elements are added to a new revString variable. The variable is then return in the display window, which is set to visible by removing the "invisibile" class element from the display.