Help: HTTP_HOST without subdomain?

[spietreser]

Hi,

I'm developing a standard for-sale parking page for my domains, but I want it to recognize the domain and dynamically output the domain name.

I have a file named something.shtml. Here I want to display the message: "Welcome to Mydomain.com"
But when I try to get the domain with HTTP_HOST it displays the subdomain (eg. "Welcome to Www.mydomain.com")

Question 1: how do I get rid of the subdomain, so the page will only display the domain without subdomains? Can this be done within the .shtml page?

Question 2:
I have a form on the page with a form that points to an email sending script in PHP. If someone enters an incorrect email address, it will display an error page (same script, .php extension). How do I get this PHP script to also output the domain without subdomain dynamically?

Many thanks in advance!

spietreser