Bootstrap email form not working properly. Is it my html or php?

Is there anything wrong with either my php or my html for my email form? Every time I submit the form online I get a blank page. I'm not sure what else I would have to change since it seems to make sense but I don't know very much about php.

<form class="form-vertical" role="form" method="post" action="index.php">
                    <fieldset>

                    <!-- Text input-->
                    <div class="form-group">
                      <label class="control-label" for="textinput">Name</label>  
                      <input id="textinput" name="textinput" type="text" placeholder="Enter Name" class="form-control input-md">
                    </div>

                    <!-- Text input-->
                    <div class="form-group">
                      <label class="control-label" for="Email">Email</label>  
                      <input id="Email" name="Email" type="text" placeholder="Enter Email" class="form-control input-md">
                    </div>

                    <!-- Text input-->
                    <div class="form-group">
                      <label class="control-label" for="Phone">Phone</label>  
                      <input id="Phone" name="Phone" type="text" placeholder="" class="form-control input-md">
                    </div>
                    </section>
                </div> <!-- end col-md-4 -->

                <div class="col-md-4 message-form">
                    <section class="wow zoomInUp" data-wow-duration="1.5s" data-wow-delay="0.2s" style="visibility: visible; -webkit-animation-delay: 0.2s; -moz-animation-delay: 0.2s; animation-delay: 0.2s;">
                    <!-- Textarea -->
                    <div class="form-group">
                      <label class="control-label" for="Message">Message</label>

                      <textarea class="form-control" rows="5" id="Message" name="Message" placeholder="Message"></textarea>
                    </div>

                    <!-- Button -->
                    <div class="form-group">
                      <label class="control-label" for="Submit"></label>
                        <button id="Submit" name="Submit" class="btn btn-primary pull-right">Send Message</button>
                    </div>
                    </fieldset>
                    </form>




<?php
if ($_POST["Submit"]) {
    $textinput = $_POST['textinput'];
    $Email = $_POST['Email'];
    $Phone = $_POST['Phone'];
    $Message = $_POST['Message'];
    $from = 'Demo Contact Form'; 
    $to = 'max.henry.campos@gmail.com'; 
    $subject = 'Message from Contact Demo ';

    $body = "From: $textinput\n E-Mail: $Email\n Message:\n $Message";

    // Check if name has been entered
    if (!$_POST['textinput']) {
        $errName = 'Please enter your name';
    }

    // Check if email has been entered and is valid
    if (!$_POST['Email'] || !filter_var($_POST['Email'], FILTER_VALIDATE_EMAIL)) {
        $errEmail = 'Please enter a valid email address';
    }

    //Check if message has been entered
    if (!$_POST['Message']) {
        $errMessage = 'Please enter your message';
    }

// If there are no errors, send the email
if (!$errtextinput && !$errEmail && !$errMessage) {
if (mail ($to, $subject, $body, $from)) {
    $result='<div class="alert alert-success">Thank You! We will be in touch</div>';
} else {
    $result='<div class="alert alert-danger">Sorry there was an error sending your message. Please try again later</div>';
}
}
}
?>