<form action="mailto:recipient@somesite.net" method="post">
Username:
<input type="text" name="user" size="20" />
<br />
Password:
<input type="password" name="password" size="20" />
<Input type="submit" name="submit" value="Send">
</form>
This will do two of the three things you want. It will display text in the first box and "stars" in the second.
It will provide a submit button that says "Send"
It, however, will not automatically send your form info via email nor auto-populate your user's message box if their browser is IE6+.
There are fixes for this, but they usually take additional software, extensions, and/or services.
See:
http://www.wickham43.supanet.com/tutorial/forms.html