To do POST you'll need to have a form.
<form action="employee.action" method="post">
<input type="submit" value="Employee1" />
</form>
There are some ways to post data with hyperlinks, but you'll need some javascript, and a form.
Some tricks: Make a link use POST instead of GET and How do you post data with a link
Edit: to load response on a frame you can target your form to your frame:
<form action="employee.action" method="post" target="myFrame">