PHP/AJAX Email form will not submit. - php

Question

I am trying to setup a fairly straight forward email form that will show a div if the email is successfully submitted and error messages when a field is not properly filled out. Currently, the Jquery side of things work, but it will not send the email. I am new to PHP, so I am not sure how to troubleshoot the PHP side of things, but all the code looks like it is correct.
HTML:
<form id="contactForm" >
<fieldset class="half float-left left">
<div class="overlay-field">
<label for="firstname" class="float-left">First Name</label>
<input id="firstname" type="text" name="firstname" >
<span id="errorFirstName" class="formError"></span>
</div>
<div class="overlay-field" data-error="">
<label for="telephone" class="float-left">Telephone</label>
<input id="telephone" type="text" name="telephone" >
<span id="errorPhone" class="formError"></span>
</div>
</fieldset>
<fieldset class="half float-right right">
<div class="overlay-field">
<label for="lastname" class="float-left">Last Name</label>
<input id="lastname" type="text" name="lastname" >
<span id="errorLastName" class="formError"></span>
</div>
div class="overlay-field" data-error="">
<label for="email" class="float-left">Email Address</label>
<input id="email" type="text" name="email" >
<span id="errorEmail" class="formError"></span>
</div>
</fieldset>
<label for="message" class="textarea-label float-left">Your Message</label>
<textarea id="message" value="Scope of Work" class="description" name="message" ></textarea>
<span id="errorMessage" class="formError"></span>
<div class="message_area">
<p class="success_message">WOOT WOOT! You're message has been sent! We will get back to you shortly.</p>
<p class="error_message">Something went wrong. Please make sure all fields are filled in properly.</p>
</div>
<button type="submit" id="submit" class="bttn bttn-4 bttn-4a">Send Message</button>
</form>
JQUERY:
$(document).ready(function() {
$('#contactForm #submit').click(function() {
$('#contactForm .formError').html('');
var isFocus=0;
var isError=0;
var firstname=$('#contactForm #firstname').val();
var lastname=$('#contactForm #lastname').val();
var email=$('#contactForm #email').val();
var telephone=$('#contactForm #telephone').val();
var message=$('#contactForm #message').val();
if(firstname=='') {
$('#contactForm #errorFirstName').html('This is a required field.');
$('#contactForm #firstname').focus();
isFocus=1;
isError=1;
}
if(lastname=='') {
$('#contactForm #errorLastName').html('This is a required field.');
$('#contactForm #lastname').focus();
isFocus=1;
isError=1;
}
if(telephone=='') {
$('#contactForm #errorPhone').html('This is a required field.');
$('#contactForm #telephone').focus();
isFocus=1;
isError=1;
}
if(email=='') {
$('#contactForm #errorEmail').html('This is a required field.');
if(isFocus==0) {
$('#contactForm #email').focus();
isFocus=1;
}
isError=1;
} else {
var reg = /^([A-Za-z0-9_\-\.])+\#([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;
if(reg.test(email)==false) {
$('#contactForm #errorEmail').html('Invalid email address.');
if(isFocus==0) {
$('#contactForm #email').focus();
isFocus=1;
}
isError=1;
}
}
if(message=='') {
$('#contactForm #errorMessage').html('This is a required field.');
$('#contactForm #message').focus();
isFocus=1;
isError=1;
}
// Terminate the script if an error is found
if(isError==1) {
return false;
}
$.ajaxSetup ({
cache: false
});
$.ajax({
type: "POST",
url: "/wp-content/themes/apds/contact-ajax.php",
data: $("#contactForm").serializeArray(),
success: function(msg) {
$(".success_message").fadeIn().delay(5000).fadeOut();
$("#contactForm")[0].reset();
$('#contactForm #submit').removeAttr("disabled");
},
error: function(ob,errStr) {
$('#contactForm #submit').removeAttr("disabled");
}
});
return false;
});
});
PHP
<?php
if(empty($_POST['firstname']) ||
empty($_POST['lastname']) ||
empty($_POST['telephone']) ||
empty($_POST['email']) ||
empty($_POST['message'])) {
die('Error: Missing variables');
}
$email_subject = "Your email subject line";
$firstname=$_POST['firstname'];
$lastname=$_POST['lastname'];
$email=$_POST['email'];
$telephone=$_POST['telephone'];
$message=$_POST['message'];
$to='my#email.com';
$headers = 'From: '.$email."\r\n" .
'Reply-To: '.$email."\r\n" .
'X-Mailer: PHP/' . phpversion();
$email_subject = $email_subject;
$body='You have got a new message from the contact form on your website.'."\n\n";
$body.='First Name: '.$firstname."\n";
$body.='Last Name: '.$lastname."\n";
$body.='Email: '.$email."\n";
$body.='Telephone: '.$telephone."\n";
$body.='Message: '."\n".$message."\n";
if(mail($to, $email_subject, $body, $headers)) {
die('Mail sent');
} else {
die('Error: Mail failed');
}
?>