jquery post call not working with slash at end of the url

example url:
Target is not to show .php extension, but content stop working when page/url is open with a slash at the end.
http://ift.tt/1F9Oyt6 - form is working with this url
http://ift.tt/1EnOLSI - form is not working with this url

Folder & files:
|
| /js/custom.js
| /manager/create.php
| /manager/creategetpostdata.php
| /manager/.htaccess

Content on custom.js

$(window).load(function() {
    // get post code data
    $('.contentfinder').on('keyup', function(e){
        var xyz = $(this).closest('.contentRow');
        //alert( "success" );
        $.post("../manager/creategetpostdata.php", xyz.find('.contentfinder').serialize(),  function(response) {
            //alert( "success" );
            xyz.children('.showPostData').html(response);
            xyz.children('.showPostData').show();
        });

    });

});

input form on create.php file:

                    <div class="contentRow">
                        <input type="text" name="inputdata" class="form-control contentfinder" placeholder="" />
                        <div class="showPostData"></div>
                    </div>

content on creategetpostdata.php

<?php echo 'hello, what the hell wrong with you. just show content now!'; ?>

content on .htaccess file

Options +FollowSymLinks -MultiViews
RewriteEngine On

RewriteCond %{THE_REQUEST} \s/+(.+?)\.php\?([^=]+)=([^\s&]+) [NC]
RewriteRule ^ /%1/%2/%3? [R=302,L,NE]

RewriteCond %{THE_REQUEST} \s/+(.+?)\.php\s [NC]
RewriteRule ^ /%1 [R=302,L,NE]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ - [L]

RewriteCond %{REQUEST_FILENAME}.php -f
RewriteRule ^(.+?)/?$ $1.php [L]

any help? thanks in advance.