First Name and Message Not shown on body of email - php

Question

i created a contact form php below, for some reason when I submit the entries, the First name shows up on the header but not the Body of the message. Same goes for message. Does anyone know the issue here?
PHP
<?php
$field_name = $_POST['first_name'];
$field_last = $_POST['last_name'];
$field_email = $_POST['cf_email'];
$field_city = $_POST['cf_city'];
$field_state = $_POST['cf_state'];
$field_postal = $_POST['cf_postal'];
$field_country = $_POST['cf_country'];
$field_profession = $_POST['cf_profession'];
$field_industry = $_POST['cf_industry'];
$field_job = $_POST['cf_job'];
$field_linkedin = $_POST['cf_linkedin'];
$field_facebook = $_POST['cf_facebook'];
$field_instagram = $_POST['cf_instagram'];
$field_message = $_POST['cf_message'];
$mail_to = 'membership#name.com';
$subject = 'Message from a site visitor '.$field_name;
$body_message = 'From: '.$field_name."\n";
$body_message = 'From: '.$field_last."\n";
$body_message .= 'E-mail: '.$field_email."\n";
$body_message .= 'City: '.$field_city."\n";
$body_message .= 'State/Province: '.$field_state."\n";
$body_message .= 'Postal: '.$field_postal."\n";
$body_message .= 'Country: '.$field_country."\n";
$body_message .= 'Profession: '.$field_profession."\n";
$body_message .= 'Industry: '.$field_industry."\n";
$body_message .= 'Job: '.$field_job."\n";
$body_message .= 'LinkedIn: '.$field_linkedin."\n";
$body_message .= 'Facebook: '.$field_facebook."\n";
$body_message .= 'Instagram: '.$field_instagram."\n";
$body_message .= 'Message: '.$field_message;
$headers = 'From: '.$field_email."\r\n";
$headers .= 'Reply-To: '.$field_email."\r\n";
$mail_status = mail($mail_to, $subject, $body_message, $headers);
if ($mail_status) { ?>
<script language="javascript" type="text/javascript">
alert('CourtSide House. Thank you for your submission');
window.location = 'index.html';
</script>
<?php
}
else { ?>
<script language="javascript" type="text/javascript">
alert('Message failed. Please, send an email to membership#name.com');
window.location = 'index.html';
</script>
<?php}?>
HTML
<pre><form method="post" action="contact.php">
<p>Contact<p>
<hr>
<div class="row half">
<div class="6u"><input type="text" class="text" placeholder="First Name*" name="first_name"></div>
<div class="6u"><input type="text" class="text" placeholder="Last Name*" name="last_name"></div>
<div class="12u"><input type="text" class="text" placeholder="Email*" name="cf_email"></div>
<div class="4u"><input type="text" class="text" placeholder="City*" name="cf_city"></div>
<div class="4u"><input type="text" class="text" placeholder="State/Province*" name="cf_state"></div>
<div class="4u"><input type="text" class="text" placeholder="Postal Code*" name="cf_postal"></div>
<div class="12u"><input type="text" class="text" placeholder="Country*" name="cf_country"></div>
<div class="4u"><input type="text" class="text" placeholder="Profession*" name="cf_profession"></div>
<div class="4u"><input type="text" class="text" placeholder="Industry*" name="cf_industry"></div>
<div class="4u"><input type="text" class="text" placeholder="Job Title*" name="cf_job"></div>
</div>
<p>Share Some Information About Yourself*<i><small class="small" id="small" style="font-size: 12px">(Please Place Link of Social Media Profile)</small></i></p>
<hr>
<div class="row half">
<div class="4u"><input type="text" class="text" placeholder="LinkedIn Profile*" name="cf_linkedin"></div>
<div class="4u"><input type="text" class="text" placeholder="Facebook Profile*" name="cf_facebook"></div>
<div class="4u"><input type="text" class="text" placeholder="Instagram Profile*" name="cf_instagram"></div>
</div
><div class="row half">
<div class="12u"><textarea name="message" placeholder="Message" ></textarea></div>
</div>
<div class="row">
<div class="12u">
<ul class="actions">
<li><input type="submit" class="button" value="Submit"></li>
</ul>
</div>
</div>
</form></pre>

Answer 1

You need to append to the variable $body_message instead of overwriting it as you do the second time you call it.
$body_message = 'From: '.$field_name."\n";
$body_message = 'From: '.$field_last."\n";
should be
$body_message = 'From: '.$field_name."\n";
$body_message .= 'From: '.$field_last."\n";

Answer 2

Probably you are confusing your e-mail clients with this:
$body_message = 'From: '.$field_name."\n";
$body_message = 'From: '.$field_last."\n";

Answer 3

1) You're missing the concatenation operator on your variable assignment:
$body_message = 'From: '.$field_name."\n";
$body_message = 'From: '.$field_last."\n";
should be
$body_message = 'From: '.$field_name."\n";
$body_message .= 'From: '.$field_last."\n";
^^^^^
HERE
2) You're message field is just called message:
$field_message = $_POST['cf_message'];
should be
$field_message = $_POST['message'];
Or change
<textarea name="message" placeholder="Message" >
to
<textarea name="cf_message" placeholder="Message" >

Answer 4

Message is not showing because you are using wrong key when retrieving it.
Update with following:
$field_message = $_POST['message']; // Textarea's name is message not cf_message
Then, first name is not showing because you're overwriting $body_message right after you assign $body_message with 'From: '.$field_name."\n";.
Update as follows:
$body_message = 'From: '.$field_name."\n";
$body_message .= 'From: '.$field_last."\n"; // Use .= not just =