function callMobilePhone($phone_num)
 {
     CellPhone::openSerialPort();
     CellPhone::callPhone($phone_num);
     CellPhone::closeSerialPort();
     $msg = 'Calling ' . $phone_num . '...<INPUT TYPE="image" SRC="' . URLHelper::getWebBaseURL() . 'images/hangup.gif" BORDER="0" >';
     $data = array("phone_num" => $phone_num, "msg" => $msg);
     return $data;
 }