'; $userkey = '';// VTDD cung cap $tong = $userkey . $id . $phone . $shortcode . $sms; $server_checksum = md5($tong); // Kiem tra id co trung khong // Luu DB // Xu ly noi dung tin nhan echo 'Noi dung can tra cho khach hang'; }else{ echo 'LOI'; } // Hex to String function hextobin($hexstr) { $n = strlen($hexstr); $sbin=""; $i=0; while($i<$n) { $a =substr($hexstr,$i,2); $c = pack("H*",$a); if ($i==0){$sbin=$c;} else {$sbin.=$c;} $i+=2; } return $sbin; } ?>