Arduino read/write serial with PHP

//PHP Code
 <?php
require("php_serial.class.php");
if (isset($_GET['action']))
{
$serial = new phpSerial;
$serial->deviceSet("/dev/ttyACM0");
$serial->confBaudRate(115200);
$serial->deviceOpen();
    if ($_GET['action'] == "greenon")
    {
    $serial->sendMessage("0");
    $done = false;
    $line = "";
        while (!$done)
        {
        $read = $serial->readPort();
            for ($i = 0; $i < strlen($read); $i++)
            {
                if ($read[$i] == "\n")
                {
                $done = true;
                echo "Response from Arduino: ".$line."\n";
                $line = "";
                }
                else
                {
                $line .= $read[$i];
                }
            }
        }
    }
    else if ($_GET['action'] == "greenoff")
    {
    $serial->sendMessage("1\r");
    }
    else if ($_GET['action'] == "redon")
    {
    $serial->sendMessage("2\r");
    $read = $serial->readPort();
    echo $read;
    }
    else if ($_GET['action'] == "redoff")
    {
    $serial->sendMessage("3\r");
    }
$serial->deviceClose();
}


?><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<title>Arduino Project 1: Serial LED Control</title>
</head>
<body>

<h1>Arduino Project 1: Serial LED Control</h1>
<p><a href="<?=$_SERVER['PHP_SELF'] . "?action=greenon" ?>">
Click here to turn pin13 on.</a></p>
<p><a href="<?=$_SERVER['PHP_SELF'] . "?action=greenoff" ?>">
Click here to turn pin13 off.</a></p>
<p><a href="<?=$_SERVER['PHP_SELF'] . "?action=redon" ?>">
Click here to turn the RED LED on.</a></p>
<p><a href="<?=$_SERVER['PHP_SELF'] . "?action=redoff" ?>">
Click here to turn the RED LED off.</a></p>
</body>
</html>

/* ##Arduino code
int ledPin13 = 13; // the pin that the green LED is attached to
int ledPin12 = 12; // the pin that the red LED is attached to
int relay = 8;
int incomingByte;      // a variable to read incoming serial data into
void setup()
{

Serial.begin(115200); // initialize serial communication

pinMode(ledPin13, OUTPUT);  // initialize the green LED pin as an output
pinMode(ledPin12, OUTPUT);  // initialize the red LED pin as an output
pinMode(relay, OUTPUT);
 }
 void loop() {
   digitalWrite(relay, HIGH);
   // see if there's incoming serial data:
   if (Serial.available() > 0) {

     incomingByte = Serial.read(); // read the oldest byte in the serial buffer
//Preform the code to switch on or off the leds
    if (incomingByte == '0') {

    digitalWrite(ledPin13, HIGH); //If the serial data is 0 turn red LED on
delay(100);
Serial.println("0");
}
   if (incomingByte == '1') {
   digitalWrite(ledPin13, LOW); //If the serial data is 1 turn red LED off
 Serial.println("1");
 }

     if (incomingByte == '2') {
    digitalWrite(ledPin12, HIGH); //If the serial data is 2 turn green LED on
Serial.println("2");
}
   if (incomingByte == '3') {
   digitalWrite(ledPin12, LOW); //If the serial data is 3 turn green LED off
 Serial.println("3");
 }

   }
 }

*/