Sending SMS using GSM Modem

Question

i wanna create a form that can send sms to multiple recipient, i've created a form that uses javascript to add or remove textbox dynamically, this code successfully send sms when i fill one recipient number, but fails to send more than one recipient, and i want to know how do i make this form sends sms towards multiple user

as i try to make it send sms to more than one user by making it loop, i get this error, Can someone help?

Warning: Invalid argument supplied for foreach()

<SCRIPT language="javascript">
        function addRow(tableID) {

            var table = document.getElementById(tableID);

            var rowCount = table.rows.length;
            var row = table.insertRow(rowCount);

            var cell1 = row.insertCell(0);
            var element1 = document.createElement("input");
            element1.type = "checkbox";
            element1.name="chkbox[]";
            cell1.appendChild(element1);

            var cell2 = row.insertCell(1);
            cell2.innerHTML = rowCount + 1;

            var cell3 = row.insertCell(2);
            var element2 = document.createElement("input");
            element2.type = "text";
            element2.name = "CTL_TEL";

            cell3.appendChild(element2);


        }

        function deleteRow(tableID) {
            try {
            var table = document.getElementById(tableID);
            var rowCount = table.rows.length;

            for(var i=0; i<rowCount; i++) {
                var row = table.rows[i];
                var chkbox = row.cells[0].childNodes[0];
                if(null != chkbox && true == chkbox.checked) {
                    table.deleteRow(i);
                    rowCount--;
                    i--;
                }


            }
            }catch(e) {
                alert(e);
            }
        }

    </SCRIPT>


<?php


error_reporting(E_ALL ^ E_NOTICE);

//Example

$gsm_send_sms = new gsm_send_sms();
$gsm_send_sms->debug = false;
$gsm_send_sms->port = 'COM6';
$gsm_send_sms->baud = 115200;
$gsm_send_sms->init();
$name="CTL_TEL[]";



foreach ($tel as $_POST['CTL_TEL']) {

$status = $gsm_send_sms->send($_POST["CTL_TEL"] , $_POST["CTL_MSG"]);
$status = $gsm_send_sms->send($tel , $_POST["CTL_MSG"]); 


if ($status) {
    echo "Message sent\n";
} else {
    echo "Message not sent\n";
}
}

$gsm_send_sms->close();







//Send SMS via serial SMS modem
class gsm_send_sms {

    public $port = 'COM6';
    public $baud = 115200;

    public $debug = false;

    private $fp;
    private $buffer;

    //Setup COM port
    public function init() {

        $this->debugmsg("Setting up port: \"{$this->port} @ \"{$this->baud}\" baud");

        exec("MODE {$this->port}: BAUD={$this->baud} PARITY=N DATA=8 STOP=1", $output, $retval);

        if ($retval != 0) {
            throw new Exception('Unable to setup COM port, check it is correct');
        }

        $this->debugmsg(implode("\n", $output));

        $this->debugmsg("Opening port");

        //Open COM port
        $this->fp = fopen($this->port . ':', 'r+');

        //Check port opened
        if (!$this->fp) {
            throw new Exception("Unable to open port \"{$this->port}\"");
        }

        $this->debugmsg("Port opened");
        $this->debugmsg("Checking for responce from modem");

        //Check modem connected
        fputs($this->fp, "AT\r");

        //Wait for ok
        $status = $this->wait_reply("OK\r\n", 5);

        if (!$status) {
            throw new Exception('Did not receive responce from modem');
        }

        $this->debugmsg('Modem connected');

        //Set modem to SMS text mode
        $this->debugmsg('Setting text mode');
        fputs($this->fp, "AT+CMGF=1\r");

        $status = $this->wait_reply("OK\r\n", 5);

        if (!$status) {
            throw new Exception('Unable to set text mode');
        }

        $this->debugmsg('Text mode set');

    }

    //Wait for reply from modem
    private function wait_reply($expected_result, $timeout) {

        $this->debugmsg("Waiting {$timeout} seconds for expected result");

        //Clear buffer
        $this->buffer = '';

        //Set timeout
        $timeoutat = time() + $timeout;

        //Loop until timeout reached (or expected result found)
        do {

            $this->debugmsg('Now: ' . time() . ", Timeout at: {$timeoutat}");

            $buffer = fread($this->fp, 1024);
            $this->buffer .= $buffer;

            usleep(200000);//0.2 sec

            $this->debugmsg("Received: {$buffer}");

            //Check if received expected responce
            if (preg_match('/'.preg_quote($expected_result, '/').'$/', $this->buffer)) {
                $this->debugmsg('Found match');
                return true;
                //break;
            } else if (preg_match('/\+CMS ERROR\:\ \d{1,3}\r\n$/', $this->buffer)) {
                return false;
            }

        } while ($timeoutat > time());

        $this->debugmsg('Timed out');

        return false;

    }

    //Print debug messages
    private function debugmsg($message) {

        if ($this->debug == true) {
            $message = preg_replace("%[^\040-\176\n\t]%", '', $message);
            echo $message . "\n";
        }

    }

    //Close port
    public function close() {

        $this->debugmsg('Closing port');

        fclose($this->fp);

    }

    //Send message
    public function send($tel, $message) {

        //Filter tel
        $tel = preg_replace("%[^0-9\+]%", '', $tel);

        //Filter message text
        $message = preg_replace("%[^\040-\176\r\n\t]%", '', $message);

        $this->debugmsg("Sending message \"{$message}\" to \"{$tel}\"");

        //Start sending of message
        fputs($this->fp, "AT+CMGS=\"{$tel}\"\r");

        //Wait for confirmation
        $status = $this->wait_reply("\r\n> ", 5);

        if (!$status) {
            //throw new Exception('Did not receive confirmation from modem');
            $this->debugmsg('Did not receive confirmation from modem');
            return false;
        }

        //Send message text
        fputs($this->fp, $message);

        //Send message finished indicator
        fputs($this->fp, chr(26));

        //Wait for confirmation
        $status = $this->wait_reply("OK\r\n", 180);

        if (!$status) {
            //throw new Exception('Did not receive confirmation of messgage sent');
            $this->debugmsg('Did not receive confirmation of messgage sent');
            return false;
        }

        $this->debugmsg("Message sent");

        return true;

    }

}

?> 






<html>
<head>
<title>SMS via GSM</title>
<meta content="text/html; charset=UTF-8" http-equiv="Content-Type">
<style>
   .clbody {
   font-family:Verdana, Arial, Helvetica, sans-serif;
   font-size:9pt;
   font-weight:normal;
}
.clfooter {
   font-family:Verdana;
   font-size:7pt;
   font-weight:normal;
}
h1, .h1 {
   width:100%;
   font-family:Verdana, Arial, Helvetica, sans-serif;
   font-size:18px;
   font-weight:bold;
}
hr, .hr {
   color:#b0b0b0;
}
</style>
</head>

<body class="clbody">
<h1>SMS via GSM</h1>
<div style="WIDTH:700px">

</div>
<hr size="1">

<?php
error_reporting(E_ALL ^ E_NOTICE);
?>
<form action="" method="post" name="myForm">
<table class ="clbody" width="700" border="1">

   <tr>
      <td valign="top">Recipient:</td>
      <td valign="top">

      <INPUT type="button" value="Add Row" onclick="addRow('dataTable')" />

    <INPUT type="button" value="Delete Row" onclick="deleteRow('dataTable')" />

    <TABLE id="dataTable" width="350px" border="1">
        <TR>
            <TD><INPUT type="checkbox" name="chk"/></TD>
            <TD> 1 </TD>
            <TD> <input type="text" name="CTL_TEL" value="<?php  echo $_GET['CTL_TEL']; ?>"> </TD>
        </TR>
    </TABLE>



     </td>
   </tr>
   <tr>
      <td valign="top">Message:</td>
      <td valign="top">



      <input style="width: 250px" type="text" name="CTL_MSG" value="<?php echo $_GET['CTL_MSG']; ?>"></td>




   </tr>

      <tr>
      <td valign="top">Result code:<font color=green></td>
      <td valign="top"></td>
   </tr>   
   <tr>
      <td valign="top">&nbsp;</td>
      <td valign="top"><input size="25" type="submit" value="Send" name="CTL_SEND" style="height: 23px; width: 250px"></td>
   </tr>
</table>
<br>
<br>
</form>



</body>
</html>