how to link mirror sites??

[rrn rose]

my website (english) in php , sql .

on the index page there's a link to the arabic site which is a mirror site of the english site.

whenever i click the link , it is directing to the index.php of arabic site.

this is the code

 <a href="/ar/index.php"><img  border="0"  /></a> 

what i need is , if i am on the site.php of english site and then i click the link it should direct to site.php of arabic site..
if i am on the abc.php of english site and then i click the link it should direct to site.php of arabic site..
likewise it should be applicable to all the php pages..

hope you understood the problem..
please help me........