<?php echo $response; ?>
  <form id="contactForm" action="<?php the_permalink(); ?>" method="post">
    <p><input class="input" type="text" name="message_name" value="<?php echo esc_attr($_POST['message_name']); ?>" placeholder="First & Last Name"></p>
    <p><input class="input" type="text" name="message_text" value="<?php echo esc_attr($_POST['message_text']); ?>" placeholder="Company name"></p>
    <p><input class="input" type="text" name="message_email" value="<?php echo esc_attr($_POST['message_email']); ?>" placeholder="Email address"></p>
    <input type="hidden" name="submitted" value="1">
    <p><input type="submit" value="Send" /></p>
  </form>

<?php
  //response generation function
  $response = "";

  //function to generate response
  function first_contact_form_generate_response($type, $message){
    global $response;
    if($type == "success") {
      $response = "<div class='text--green'>{$message}</div>";
      $_POST = array();
    } else {
      $response = "<div class='text--red'>{$message}</div>";
    }
  }

  //response messages
  $missing_content = "Please supply all information.";
  $email_invalid   = "Email Address Invalid.";
  $message_unsent  = "Message was not sent. Try Again.";
  $message_sent    = "Thank you! Your request has been sent.";

  //user posted variables
  $name = $_POST['message_name'];
  $email = $_POST['message_email'];
  $message = 'Full name: ' . "rn" . $name . "rnrn" . 'Company name: ' . "rn" . $_POST['message_text'] . "rnrn" . 'Email address: ' . "rn" . $email;

  //php mailer variables
  $to = "email@site.com";
  $subject = "Request by ".$email;
  $headers = 'From: '. $email . "rn" .
    'Reply-To: ' . $email . "rn";

  //validate email
  if ($_POST['submitted']) {
  if(!filter_var($email, FILTER_VALIDATE_EMAIL)){
    first_contact_form_generate_response("error", $email_invalid);
  }
  else //email is valid
  {
    //validate presence of name and message
    if(empty($name) || empty($message)){
      first_contact_form_generate_response("error", $missing_content);
    }
    else //ready to go!
    {
      $sent = wp_mail($to, $subject, strip_tags($message), $headers);
      if($sent) first_contact_form_generate_response("success", $message_sent); //message sent!
      else first_contact_form_generate_response("error", $message_unsent); //message wasn't sent
    }
  }
  } else if ($_POST['submitted']) first_contact_form_generate_response("error", $missing_content);
?>