在子目录中使用时，所有表单值都为空

I have a contact us page in a website made for a client, which I am hosting from a sub-directory of my main website. When someone sends a message from "contact us" page, its sent to the website owner's email, but the values are empty. But when I tested the same two pages from the root directory they worked fine.

Following is the code.

HTML PAGE

<form id="main-contact-form" class="contact-form" name="contact-form" method="post" action="sendemail.php" role="form">
<div class="row">
    <div class="col-sm-5">
        <div class="form-group">
            <input name="fname" type="text" class="form-control" required="required" placeholder="First Name">
        </div>
        <div class="form-group">
            <input name="lname" type="text" class="form-control" required="required" placeholder="Last Name">
        </div>
        <div class="form-group">
            <input name="email" type="text" class="form-control" required="required" placeholder="Email address">
        </div>
        <div class="form-group">
            <button type="submit" class="btn btn-primary btn-lg">Send Message</button>
        </div>
    </div>
    <div class="col-sm-7">
        <textarea name="message" id="message" required="required" class="form-control" rows="8" placeholder="Message"></textarea>
    </div>
</div>
</form>

PHP FILE

<?php
header('Content-type: application/json');
$status = array(
    'type'=>'success',
    'message'=>'Email sent!'
);

$fname= @trim(stripslashes($_POST['fname'])); 
$lname = @trim(stripslashes($_POST['lname'])); 
$name = $fname.' '.$lname;
$email = @trim(stripslashes($_POST['email'])); 
$message = @trim(stripslashes($_POST['message'])); 

$email_from = $email;
$email_to = 'my.email@gmail.com';

$body = 'Name: ' . $name . "

" . 'Email: ' . $email . "

" . 'Message: ' . $message;

$success = @mail($email_to, 'An email from website\'s form', $body, 'From: <'.$email_from.'>');

echo json_encode($status);
die;

When I put both of these files in the root (public_html) through CPanel's file manager, they work fine, but if I put them in the sub-folder than the values are empty.

Following are the examples.

Example 1, when sent from the sub-folder




Example 2, when sent form the main directory

check your file "main.js" and replace:

$.post($(this).attr(‘action’), function(data) {

for

$.post($(this).attr('action'), $('.contact-form').serialize(), function(data) {

the complete "main.js" is:

jQuery(function($) {

    //Ajax contact
    var form = $('.contact-form');
        form.submit(function () {
            $this = $(this);
            $.post($(this).attr('action'), $('.contact-form').serialize(), function(data) {
            $this.prev().text(data.message).fadeIn().delay(3000).fadeOut();
        },'json');
        return false;
    });

    //Goto Top
    $('.gototop').click(function(event) {
         event.preventDefault();
         $('html, body').animate({
             scrollTop: $("body").offset().top
         }, 500);
    });
    //End goto top

});