SMS send via SOAP

i have the code to send SMS via Web Service SOAP bellow:

  /* DATABASE CONECT */
$soapClient = new SoapClient(WEST_SOAP_WSDL,
 array("login" => WEST_SOAP_LOGIN, "password" => WEST_SOAP_PASS, 'compression' => S    OAP_COMPRESSION_ACCEPT | SOAP_COMPRESSION_GZIP | 9));



 try {
   $cliente = $soapClient->getClientDataByDoc($_POST['id']); 
error_log('soapClient ' . $cliente->id);
 } catch (Exception $e) {





   exit(“not find doc");
  }


 $telefone = '55' . $cliente->telefones[1]->ddd . $cliente->telefones[1]->numero;
$soapClient->enviarSMS($telefone, "teste");
 echo (“sms send to: "),($telefone);

How Can I Start to code a Code verification in that ? example: i want to create a ramdom code to sms phone to my clients, but a i want a simple php + sql to create ramdom codes to submit to a client Area