Shirts directory files not working with .htaccess and clean URLs

I was not able to get the shirts page, nor the shirt detail page links to work with the download files.

The .htaccess Rewrite lines seemed to be working only to point the browser to the shirts/ directory, but stop short of loading the shirts.php or shirt.php file. In fact I would land on the shirts/ directory page with the files listed. I could follow the link to the shirts.php, but could not link to the shirt detail page through the shirt.php.

I was able to re-dirty the URLs on the shirts detail page and change the shirts.php to an index.php; and this is working to go forward with this course. I also had to remove the offending lines from the .htaccess folder dealing with shirts/, shirts.php and shirt.php.

I spent a good amount of time getting aquanited with .htaccess files, but sot nowhere in the end. If anyone else encountered this or found a solution, please let me know!

Here is the .htaccess file. It is the same as from the download, but with subdirectory/ added where necessary:

RewriteEngine On

RewriteRule ^subdirectory/shirts/$ mikesshirtssql/shirts/shirts.php

RewriteRule ^subdirectory/shirts/([0-9]+)/$ shirts/shirt.php?id=$1

RewriteRule ^receipt.php$ /receipt/ [R=301]

RewriteRule ^contact.php$ /contact/ [R=301]

RewriteRule ^shirts.php$ /shirts/ [R=301]

RewriteRule ^(shirts/[0-9]+)$ /$1/ [R=301]

RewriteCond %{QUERY_STRING} ^id=([0-9]+)$

RewriteRule ^shirt.php$ /shirts/%1/? [R=301]

Again, what happens is that when you link or navigate to localhost/subdirectory/shirts/ you are taken to the geneic directory page displaying links to shirts.php and shirt.php. This file is supposed to direct to the shirt.php file, without having to change the name to index.php. The larger problem is the shirt query strings don't get directed to shirt.php, as is also the intent of this file.