what are the right Rewritting urls

I have a site where I want all the url like:
www.sitio.com/city/category/nombreitem
I made a friendly url that are running when I have not chosen any city in a scrolling list of cities on my site.
The rules are:

RewriteRule     ^(.*)/(.*)/(.*)/(.*)?$                    /index.php?city=1$&ct=$2&md=details&id=$4  
RewriteRule     ^-(.*)/(.*)?$                             /index.php?city=$1&ct=$2   
RewriteRule     ^-(.*)?$                                  /index.php?ct=$1  

PHP:

Then on any items category when I click on any item I have a URL like:

www.sitio.com /-city / category / nombreitem

Note the "-" sign I have, I won´t this but I can´t, but in the worst case I will be ok with that.

BUT when I choose a city from the main cities selection and it filter all ads from that specific city, then the generated url when I enter an item is:

www.sitio.com /-city / city / category / nombreitem

So, I have repeated twice the city in the url and that's what I do not want!

But... how to take it off?

thanks.

 

Try using explode('/', $_SERVER['QUERY_STRING']), then you get an array with all parameters so you can buid-up all links you want.