Unusual Fatal Error with required files - php

Question

Im trying to design a registration page with a drop down box in it. This requires 2 database connections one to send the data to the database upon hitting the registration button and the other to pull information from the database to populate the drop down box. I had this script working flawless until a few days ago when i uploaded a file that has no relation to the other files other than a require statement to get the config.inc.php (for db connection and error handling purposes.) This file is used on almost in all my scripts and works fine on all but a few scripts in my website. After this file was uploaded the section of my registration sript populates the drop down box nolonger works.
Below is the sript in question (I have omited the datavalidation and most of the html sections i can re-add them if needed.)
<?php
require_once('includes/config.inc.php');
$page_title = 'Register';
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
require_once(MYSQL);
$trimmed = array_map('trim', $_POST);
$fn = $ln = $usr = $pw = $bd = $gs = $bs = FALSE;
//DATA VALIDATION
//END DATA VALIDATION
if($fn && $ln && $usr && $e && $pw && $bd && $gs && $bs) {
$q = "SELECT user_id FROM Users WHERE email='$e'";
$r = mysqli_query ($dbc, $q) or trigger_error("Query: $q\n<br/>MySQL Error: " . mysqli_error($dbc));
if (mysqli_num_rows($r) == 0) {
$a = md5(uniqid(rand(), true));
$q = "INSERT INTO Users (first_name, last_name, user_name, email, password1, birthdate, gamespy_id, base, active, registration_date) VALUES ('$fn', '$ln', '$usr', '$e', SHA1('$pw'), '$bd', '$gs', '$bs', '$a', NOW() )";
$r = mysqli_query($dbc, $q) or trigger_error("Query: $q\n <br/>MySQL Error:" . mysqli_error($dbc));
if (mysqli_affected_rows($dbc) == 1){
$body = "Thank you for registering with Gateway Aviation. To activate your account, please click on this link:\n\n";
$body .= BASE_URL . 'activate.php?x=' . urlencode($e) . "&y=$a";
mail($trimmed['email'],'Registration Confirmation', $body, 'From: noreply#virtual-aviation.org');
echo '<h3> Thank you for registering! A confirmation email has been sent to your address. Please click on the link in that email in order to activeate your accout.</h3>';
exit();
} else {
echo '<p class="error>You could not be registered due to a system error. We apologize for any inconvenience.</p>';
}
} else {
echo '<p class="error"> That email has already been registered. If you have forgotten your password, use the link to reset it.</p>';
}
} else {
echo '<p class="error">Please try again</p>';
}
}
?>
<td><input type='text' name='gamespyid' value='<?php if(isset($trimmed['gamespyid'])) echo $trimmed['gamespyid'];?>'/></td>
</tr>
<td>Base:</td>
<td><select name="base" size="1">
<option>
Select One
</option>
<?php
require_once(MYSQL);
$q = "SELECT airport_id, CONCAT_WS(' ', airport_code,' - ' airport_name) FROM airports ORDER BY airport_code ASC";
$r = mysqli_query ($dbc, $q);
if (mysqli_num_rows($r) > 0) {
while ($row = mysqli_fetch_array ($r, MYSQLI_NUM)) {
echo "<option value=\"$row[0]\"";
if (isset($_POST['existing']) && ($_POST['existing'] == $row[0]) ) echo 'selected="selected"'; echo ">$row[1]</option>\n";
}
} else {
echo '<option>Please a new airport first.</option>';
}
mysqli_free_result($result);
?>
</select></td>
</table>
<input type='submit' name='submit' value='Register'/>
</form>
</body>
</html>
Im also getting this error in my error log
[20-Aug-2012 03:09:25] PHP Fatal error: Cannot redeclare my_error_handler() (previously declared in /home5/virtua15/public_html/gatewayaviation/includes/config.inc.php:36) in /home5/virtua15/public_html/gatewayaviation/includes/config.inc.php on line 56

Answer 1

you should have
require_once('includes/config.inc.php');
require_once(MYSQL);
but why do you require the config and MYSQL twice? Once it's enough for the entire script, it will work for any IF statements if you start with them.

Answer 2

Use
require_once('includes/config.inc.php');
at the top and remove the second require('includes/config.inc.php'); instance.
Keep the connection open and only close it at the end of the script. Rather dispose of results once you have pulled the data from the database using mysqli_free_result($result);