.htaccess rewrite rule not behaving as expected

I am attempting to have http://mysite.com/orders/10000111 rewritten to http://mysite.com/orders/details.pl/10000111

Here is what I have in my .htaccess

RewriteEngine On
RewriteBase /
RewriteCond %{SCRIPT_FILENAME} ^orders\/([0-9]+)
RewriteRule ^orders\/([0-9]+)$ orders/details.pl/$1 [NS,NC,QSA]

Can someone help out and tell me how I am 开发者_运维问答being an idiot?

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no need to escape / as in \/

Options +FollowSymlinks
RewriteEngine on
RewriteRule ^orders/([0-9]+)$ /orders/details.pl/$1 [NC]

should do the job