Need help with SMS script...

I use the SMS script on this page:
http://www.prescriptionpc.com/TEST_newpage1.html#section=sms

The �functions� work fine, but after clicking �submit� and receiving the
�thank you� message, nothing happens.

I find it odd that I can send a text message to myself choosing my carrier (Virgin Mobile),
but if someone else selects another carrier, nothing happens.

=================================================================

I use the following php form to process the form:

 
<?php
/*
Credits: Bit Repository
URL: http://www.bitrepository.com/
*/
 
include 'smssender.php';
 
error_reporting (E_ALL ^ E_NOTICE);
 
$post = (!empty($_POST)) ? true : false;
 
if($post)
{
 
$from = $_POST['from'];
$to = $_POST['to'];
$carrier = $_POST['carrier'];
$message = stripslashes($_POST['message']);
 
 
$error = '';
 
// Check name
 
if(!$from)
{
$error .= 'Please Enter Your Number.<br />';
}
 
 
// Check message (length)
 
if(!$message || strlen($message) < 15)
{
$error .= "Your message should have at least 15 characters.<br />";
}
 
 
if(!$error)
{
$mail = mail($formatted_number, "TXT Message", $message, $headers);
 
 
if($mail)
{
echo 'OK';
}
 
}
else
{
echo '<div class="notification_error">'.$error.'</div>';
}
 
}
?>

=========================================================

I�ve added the INCLUDE function to include the following file:

<?php
$from = $_POST['from'];
$to = $_POST['to'];
$carrier = $_POST['carrier'];
$message = stripslashes($_POST['message']);
 
if ($carrier == "verizon") {
$formatted_number = $to."@vtext.com";
mail("$formatted_number", " TXT Message", "$message" , "$headers");
 
}
 
else if ($carrier == "tmobile") {
$formatted_number = $to."@tomomail.net";
mail("$formatted_number", " TXT Message", "$message" , "$headers");
 
}
 
else if ($carrier == "sprint") {
$formatted_number = $to."@messaging.sprintpcs.com";
mail("$formatted_number", " TXT Message", "$message" , "$headers");
 
}
 
else if ($carrier == "att") {
$formatted_number = $to."@txt.att.net";
mail("$formatted_number", " TXT Message", "$message" , "$headers");
 
}
 
else if ($carrier == "virgin") {
$formatted_number = $to."@vmobl.com";
mail("$formatted_number", " TXT Message", "$message" , "$headers");
 
}
 
?>

=========================================================

Is there ANY way of finding out where I went wrong in my code?

Thanks in advance,
Bruce