Ceon URI Mapping (SEO)

[bn17311]

so

<?php
if ($_GET['main_page'] == 'create_account' && CREATE_ACCOUNT_VALIDATION == 'true' || $_GET['main_page'] == 'login' && LOGIN_VALIDATION == 'true') { 
?>

<?php
  if ($is_read_only == false || $_GET['main_page'] == 'create_account' || $_GET['main_page'] == 'login') {
    $sql = "DELETE FROM " . TABLE_ANTI_ROBOT_REGISTRATION . " WHERE timestamp < '" . (time() - 3600) . "' OR session_id = '" . zen_session_id() . "'";
    if( !$result = $db->Execute($sql) ) { die('Could not delete validation key'); }
    $reg_key = generate_captcha_code();
    $sql = "INSERT INTO ". TABLE_ANTI_ROBOT_REGISTRATION . " VALUES ('" . zen_session_id() . "', '" . $reg_key . "', '" . time() . "')";
    if( !$result = $db->Execute($sql) ) { die('Could not check registration information'); }
?>

and

<?php
if ($_GET['main_page'] == 'contact_us') && CONTACT_US_VALIDATION == 'true' { 
?>

<?php
  if ($is_read_only == false || ($_GET['main_page'] == 'contact_us')) || (strstr($_SERVER['REQUEST_URI'],'login'))) {
    $sql = "DELETE FROM " . TABLE_ANTI_ROBOT_REGISTRATION . " WHERE timestamp < '" . (time() - 3600) . "' OR session_id = '" . zen_session_id() . "'";
    if( !$result = $db->Execute($sql) ) { die('Could not delete validation key'); }
    $reg_key = generate_captcha_code();
    $sql = "INSERT INTO ". TABLE_ANTI_ROBOT_REGISTRATION . " VALUES ('" . zen_session_id() . "', '" . $reg_key . "', '" . time() . "')";
    if( !$result = $db->Execute($sql) ) { die('Could not check registration information'); }
?>

is this the correct way ?

thanks for your help
bryan