Event playground

by Anton

HTML

<!doctype html>
<html>
  <body>
    <div id="wrapper">JavaScript is fun!</div>
    <input type="text" name="myNum1" onkeypress="numCheck()">
    <input type="text" name="myNum2" onkeypress="numCheck2()">
    <input type="text" name="ant" onkeypress="antCheck()">
    <script>
      function numCheck() {
        message("Number: " + !isNaN(event.key));
        return !isNaN(event.key);
      }
      function numCheck2() {
        message("Not a number: " + isNaN(event.key));
        return isNaN(event.key);
      }
      function message(m) {
        document.getElementById('wrapper').innerHTML = m;
      }
      function antCheck() {
        if (event.key === 'a') {
        	event.preventDefault();
        	return false; // If it were JQuery
        }
      }
    </script>
  </body>
</html>