my ($u_firstname, $u_lastname) = ("Bogus", "Bogus");

if (param('firstname') =~ /^([a-zA-Z]+)$/) {
         $u_firstname = $1;
} else {
	# handle bogus case
}

if (param('lastname') =~ /^([a-zA-Z]+)$/) {
         $u_lastname = $1;
} else {
	# handle bogus case
}