I already showed you. I'll repeat myself, though it pains me to do so.

$sth = $dbh->prepare(
  "SELECT username FROM users WHERE username=?"
);
$sth->execute(param("username"));
if ($sth->fetchrow_array) {
  error("The username already exists.");
}
[download]

_____________________________________________________
Jeff[japhy]Pinyan: Perl, regex, and perl hacker, who'd like a job (NYC-area)
s++=END;++y(;-P)}y js++=;shajsj<++y(p-q)}?print:??;