Рекомендую реализовать данный скрипт без JS, и только потом, когда будет готов .php, внедрять ajax
Options -Indexes
ErrorDocument 404 /404.php
<IfModule mod_php5.c>
php_flag allow_call_time_pass_reference 1
php_flag session.use_trans_sid off
#php_value display_errors 1
php_value max_input_vars 10000
php_value pcre.recursion_limit 100
php_value default_socket_timeout 60
php_value mbstring.func_overload 2
php_value mbstring.internal_encoding UTF-8
</IfModule>
<IfModule mod_rewrite.c>
Options +FollowSymLinks
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-l
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_URI} ^(.*/[^/\.]+)$
RewriteRule ^(.*)$ http://%{HTTP_HOST}/$1/ [R=301,L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-l
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !/bitrix/urlrewrite.php$
RewriteRule ^(.*)$ /bitrix/urlrewrite.php [L]
RewriteRule .* - [E=REMOTE_USER:%{HTTP:Authorization}]
</IfModule>
<IfModule mod_dir.c>
DirectoryIndex index.php index.html
</IfModule>
<IfModule mod_expires.c>
ExpiresActive on
ExpiresByType image/jpeg "access plus 3 day"
ExpiresByType image/gif "access plus 3 day"
</IfModule>
ErrorDocument 404 /404.php