<html>
<body>
<h1>What is your name?</h1>
<form name="testform" action="/example/html/form_action.aspx"
onSubmit="alert('Hello ' + testform.inputfield.value +'!')">
<input type="text" name="inputfield" size="20">
<input type="submit" value="Submit">
</form>
</body>
</html>