you need to make a copy of the contactus.php page for the second contact form. and also make a copy of the WA_Globals.php file, save that as WA_Globals2.php.
In the second contact form, change the include reference:
<?php require_once('WA_Globals/WA_Globals.php');?>
to point to the second globals file:
<?php require_once('WA_Globals/WA_Globals2.php');?>