Add extra fields to contact form

Hi - I am trying to add extra input fields to simple email contact form. I have the basics working OK: name; email; message. The client wants a whole list of other questions too.
I’ve started by trying to add the company name. No data from this input field shows in the test mails. I’m sure the problem is in my PHP formatting. Really searched all forums and knowledge bases for simple advice but to no avail. Does anyone have a useful link for me or can you spot the error? Would appreciate any help at this stage. Thanks

PHP code:

<?php
$to = "conradspamer@gmail.com";
$subject = ($_POST[‘senderName’]);
$headers = ($_POST[‘senderCompany’]);
$message = ($_POST[‘senderMsg’]);
$message .= "


";
$message .= “E-mail Sent From: " . $_POST[‘senderName’] . " <” . $_POST[‘senderEmail’]

. ">
";
$headers = “From: " . $_POST[‘senderName’] . " <” . $_POST[‘senderEmail’] . ">
";
if(@mail($to, $subject, $message, $headers))
{
echo “answer=ok”;
}
else
{
echo “answer=error”;
}
?>

AS3 code:

submit_btn.addEventListener(MouseEvent.CLICK, sendMessage);
function sendMessage(e:MouseEvent):void{
var my_vars:URLVariables = new URLVariables();
my_vars.senderName = name_txt.text;
my_vars.senderEmail = email_txt.text;
my_vars.senderCompany = company_txt.text;
my_vars.senderMsg = message_txt.text;

var my_url:URLRequest = new URLRequest(“mail.php”);
my_url.method = URLRequestMethod.POST;
my_url.data = my_vars;

var my_loader:URLLoader = new URLLoader();
my_loader.dataFormat = URLLoaderDataFormat.VARIABLES;
my_loader.load(my_url);

name_txt.text = “”;
email_txt.text = “”;
company_txt.text = “”;
message_txt.text = “Message Sent”;

}