my @required = qw(name site siteid email email2 pass repass);
my ($site_id) = $q->param('siteid');
my $req_err;
for (@required) {
  next if $q->param($_);
  $req_err++; last;
}
if ($req_err) {
  &error("You forgot some required fields");
}
elsif ($q->param('email') ne $q->param('email2')) {
  &error("The two e-mail addresses you entered don't match");
}
elsif($q->param('pass') ne $q->param('repass')) {
  &error("Your passwords don't match");
 }
elsif (-d "/var/www/virtual/webewebin.com/home/$site_id") {
    &error("Directory already exists");
}
else {
}
[download]

That worked just fine, if I would of done this

$q->param('siteid') =~ /^\s*(\d+)\s*$/;
[download]

Then it says everysite id exists, if I would of just did

my ($site_id) = $q->param('siteid');
[download]

It would work fine