<!DOCTYPE html>
<html>
<body>
<div>
<button onClick="doNav();">
First Button
</button>
</div>
</body>
<script>
function doNav() {
window.parent.doNavFunc();
}
</script>
</html>
<!DOCTYPE html>
<html>
<body>
<div>
<button onClick="doNav();">
First Button
</button>
</div>
</body>
<script>
function doNav() {
window.parent.doNavFunc();
}
</script>
</html>