Simple yet stupid - Newbie to Postgre

[bibbydee]

I have inherited a php postgresql site problem.
It requires a unique username for a members section.
When someone runs the script it does not stop when the database shows that the username is taken and insert the username value and then shows the user that the username is taken ??? I really need a response. end or something. to stop the script cold if the username is taken.

See code below:
********************************************************************************/
$sqlstr = "SELECT id FROM users WHERE login = '".$login."'";
$result = query($sqlstr);
if (num_rows($result) != 0) {
if ($html) { header("Location: /html/$lang/reg_error6.html"); die();} else { die ("error=".urlencode("login already taken.")); }
}

    /********************************************************************************
          insert the new user into the db
    ********************************************************************************/
$HTTP_SESSION_VARS["login"]=$login;
$sqlstr = "INSERT INTO users (firstname, middlename, lastname, email,age, sex, ";
$sqlstr .= "language, country, userlevelid, login, password) ";
$sqlstr .= "VALUES ('$firstname', '$middlename', '$lastname','$email', '$age', '$sex',";
$sqlstr .= "'$language', '$country', '$userlevelid', '$login', '$password')";
$result = query($sqlstr);

$senderId = get_userid($login);        // get the newly inserted user's id # (confusing var name here)
if (!$result) die ("error=".urlencode('cant add user to db'));    //error-handle in case INSERT failed

---

[pdaoust]

hmmmmm... dunno. One question: what does the $html variable do?

Regardless of what $html does, there doesn't seem to be any problem. It should stop if the username already exists. One thought is that the header() function can only be called if there's been no other output yet. (And that includes blank spaces before your <?PHP tag.)