function cleanGlobal($global_array, $arg, $specialchars = true, $default = null) {
if(key_exists($arg, $global_array) && $global_array[$arg] != null && $global_array[$arg] != "") {
if($specialchars) {
return htmlspecialchars($global_array[$arg]);
} else {
return $global_array[$arg];
}
} else {
return $default;
}
}