function page_execute()
{
    // send customers usage alerts
    print "Checking customer usage alerts...\n";
    $return = service_usage_alerts_generate(NULL);
    if ($return == -1) {
        print "No alerts sent - EMAIL_ENABLE is disabled.\n";
    }
    print "Alerting complete.\n";
}
    $id_service_customer = @security_script_input('/^[0-9]*$/', $_GET["id_service_customer"]);
    // make sure the customer actually exists
    $sql_obj = new sql_query();
    $sql_obj->string = "SELECT id FROM `customers` WHERE id='{$id}' LIMIT 1";
    $sql_obj->execute();
    if (!$sql_obj->num_rows()) {
        $_SESSION["error"]["message"][] = "The customer you have attempted to view - {$id} - does not exist in this system.";
    }
    //// ERROR CHECKING ///////////////////////
    /// if there was an error, go back to the entry page
    if ($_SESSION["error"]["message"]) {
        header("Location: ../index.php?page=customers/service-history.php&id_customer={$id}&id_service_customer={$id_service_customer}");
        exit(0);
    } else {
        // execute functions
        //
        // note: this will actually check all services for the customer, not just the selected one, but this
        // is not a bad thing and there is no reason not to, unless performance becomes an issue.
        //
        service_usage_alerts_generate($id);
        // display updated details
        header("Location: ../index.php?page=customers/service-history.php&id_customer={$id}&id_service_customer={$id_service_customer}");
        exit(0);
    }
    /////////////////////////
} else {
    // user does not have perms to view this page/isn't logged on
    error_render_noperms();
    header("Location: ../index.php?page=message.php");
    exit(0);
}