Organizing Your Controllers into Sub-folders

[eluser]myjeep_2003[/eluser]
First of I am newbie and last time I posted here regarding database class was resolved so quickly... it is sweet... great community..........

OK now to my simple question........

I am organizing my views separate folder as per the manual

application/controllers/products/shoes.php

To call the above controller your URI will look something like this:
example.com/index.php/products/shoes/show/123


Now I have similar thing..........
application/controllers/usr_mgt/register.php

so I should be calling the controller like

example.com/index.php/usr_mgt/register???

I tried to hit the URL
example.com/index.php/usr_mgt/register


I tried to hit the URL
example.com/index.php/usr_mgt/register/show/123

but No luck.....What am I doing wrong???

But question is what *******/shoes/show/123 ***** DOOO??.... Say if I have several controller in
application/controllers/usr_mgt/ how do I call them??

Thanks a lot........