//add this to your processor.php page
<?php
echo "Here is the info you sent:<br/>\n";
foreach($_POST as $key => $value) 
{
echo $key."=".$value."<br/>\n";
}
$to = "ben@fieldii.com";
$subject = "Web contact";
$message = $_POST['message'];
$from = "from:".$_POST['email'];
mail($to,$subject,$message,$from);
echo "Mail Sent.";
?>

<!--add to your html-->
<form action="processor.php" name="contact_form" class="above" method="post">
<fieldset>
<legend>Contact form</legend>
<label for="first">First</label><input type="text" name="first_name" id="first_name">
<label for="last">Last</label><input type="text" name="last_name" id="last_name">
<label for="email">Email</label><input type="text" name="email" id="email">
<label for="message">Message</label><textarea name="message" rows="10" cols="20"></textarea>
<br />
<input type="submit">
</fieldset>
</form>

Rendered

Contact form