<!DOCTYPE html>
<html>
<head>
<script>
function writeMessage() {
document.forms[0].mySecondInput.value = document.forms[0].myInput.value;
}
</script>
</head>
<body>
<p>The onkeyup event occurs when the a keyboard key is on it's way UP.</p>
<form>
Enter your name:
<input type="text" name="myInput" onkeyup="writeMessage()" size="20">
<input type="text" name="mySecondInput" size="20">
</form>
</body>
</html>