BuatInterfaceTextBoxtoAlert

<!DOCTYPE html>
<html lang="en" dir="ltr">
  <head>
    <meta charset="utf-8">
    <title>Vadlan Ramdani-XIRPL3</title>
  </head>
  <body>
    <script type="text/javascript" language="javascript">
      function sayHalo()
      {
        var nm = document.getElementById('nama').value;
        alert("Halo, " + nm);
      }
    </script>
    <label>Tulis Disini</label>
    <input type="text" id="nama" onchange="sayHalo();">
  </body>
</html>