Need help on simple send mail php script

<?php
/*
This first bit sets the email address that you want the form to be submitted to.
You will need to change this value to a valid email address that you can access.
*/
$webmaster_email = "myemailaddress";

/*
This bit sets the URLs of the supporting pages.
If you change the names of any of the pages, you will need to change the values here.
*/
$feedback_page = "http://www.somewhere.com";
$error_page = "http://www.somewhere.com";
$thankyou_page = "http://www.somewhere.com";

/*
This next bit loads the form field data into variables.
If you add a form field, you will need to add it here.
*/
$persons_name = $_REQUEST['persons_name'] ;
$email_address = $_REQUEST['email_address'] ;
$phone_number = $_REQUEST['phone_number'] ;
$website = $_REQUEST['website'] ;
$requirements = $_REQUEST['requirements'] ;
$referal = $_REQUEST['referal'] ;
$budget = $_REQUEST['budget'] ;
$deadline = $_REQUEST['deadline'] ;
$furtherinfo = $_REQUEST['furtherinfo'] ;

/*
The following function checks for email injection.
Specifically, it checks for carriage returns - typically used by spammers to inject a CC list.
*/
function isInjected($str) {
	$injections = array('(\n+)',
	'(\r+)',
	'(\t+)',
	'(%0A+)',
	'(%0D+)',
	'(%08+)',
	'(%09+)'
	);
	$inject = join('|', $injections);
	$inject = "/$inject/i";
	if(preg_match($inject,$str)) {
		return true;
	}
	else {
		return false;
	}
}

// If the user tries to access this script directly, redirect them to the feedback form,
if (!isset($_REQUEST['email_address'])) {
header( "Location: $feedback_page" );
}

// If the form fields are empty, redirect to the error page.
elseif (empty($persons_name) || empty($email_address)) {
header( "Location: $error_page" );
}

// If email injection is detected, redirect to the error page.
elseif ( isInjected($email_address) ) {
header( "Location: $error_page" );
}

// If we passed all previous tests, send the email then redirect to the thank you page.
else {
mail( "$webmaster_email", "Feedback Form Results",
  $persons_name, $website, $phone_number, $email_address, $requirements, $budget, $deadline, $furtherinfo, $referal, "From: $email_address" );
header( "Location: $thankyou_page" );
}
?>

<?php
/*
This first bit sets the email address that you want the form to be submitted to.
You will need to change this value to a valid email address that you can access.
*/
$webmaster_email = "enter your email address here";

/*
This bit sets the URLs of the supporting pages.
If you change the names of any of the pages, you will need to change the values here.
*/
$feedback_page = "url of webpage that form resides on";
$error_page = "url of error page";
$thankyou_page = "url of thanks page";

/*
This next bit loads the form field data into variables.
If you add a form field, you will need to add it here.
*/
$persons_name = $_REQUEST['persons_name'] ;
$email_address = $_REQUEST['email_address'] ;
$phone_number = $_REQUEST['phone_number'] ;
$website = $_REQUEST['website'] ;
$requirements = $_REQUEST['requirements'] ;
$referal = $_REQUEST['referal'] ;
$budget = $_REQUEST['budget'] ;
$deadline = $_REQUEST['deadline'] ;
$furtherinfo = $_REQUEST['furtherinfo'] ;

/*
The following function checks for email injection.
Specifically, it checks for carriage returns - typically used by spammers to inject a CC list.
*/
function isInjected($str) {
	$injections = array('(\n+)',
	'(\r+)',
	'(\t+)',
	'(%0A+)',
	'(%0D+)',
	'(%08+)',
	'(%09+)'
	);
	$inject = join('|', $injections);
	$inject = "/$inject/i";
	if(preg_match($inject,$str)) {
		return true;
	}
	else {
		return false;
	}
}

// If the user tries to access this script directly, redirect them to the feedback form,
if (!isset($_REQUEST['email_address'])) {
header( "Location: $feedback_page" );
}

// If the form fields are empty, redirect to the error page.
elseif (empty($persons_name) || empty($email_address) || empty($phone_number) || empty($website) || empty($requirements) || empty($referal) || empty($budget) || empty($deadline) || empty($furtherinfo)) {
header( "Location: $error_page" );
}

// If email injection is detected, redirect to the error page.
elseif ( isInjected($email_address) ) {
header( "Location: $error_page" );
}

// If we passed all previous tests, send the email then redirect to the thank you page.
else {
mail( "$webmaster_email", "Quote request", 

"$persons_name,

$email_address,

$phone_number,

$website,

$requirements,

$referal,

$budget,

$deadline,

$furtherinfo", 

"From: $email_address" );
header( "Location: $thankyou_page" );
}
?>