# This is untested -- no perl here
my $sth = $dbh->prepare("SELECT name FROM members WHERE username = ?");

$sth->execute($username);  # this replaces the '?' above

if ($sth->rows != 0) {
  my $user = $sth->fetchrow_array;
  print "This username is in use by $user.  Try another username.\n";
} else {
  $sth = $dbh->prepare("INSERT INTO member (username, password, email, name, url, date) VALUES (?, ?, ?, ?, ?, ?)");
  $sth->execute($username, $password, $email, $name, $url, $time);
  print "User Created Normally";
}