title: What is missing on this JS code to make it looping
body: <p>What is missing on this basic code to make it looping when the prompt input give error?</p>
  
  <pre><code>var userChoice = prompt("Do you choose rock, paper or scissors?");
  var error = "Error. You should input rock, paper or scissors!";
  var inputAgain = "Do you choose rock, paper or scissors?";
      if(userChoice!=="rock") {
          if(userChoice!=="paper") {
              if(userChoice!=="scissors") {
                  confirm(error);
                  userChoice = prompt("Do you choose rock, paper or scissors?");
              }
          }
      }
  </code></pre>