<!DOCTYPE html>
<html>
<head>
<script>
function f() {
document.write("function f()");
}
</script>
</head>
<body>
<form method = "POST" action = "" onsubmit = "return f()">
<input type = "submit" value = "Submit" />
</form>
</body>
</html>
<!--
run:
function f()
-->