assigning links to a variable

Hi, sorry but I had no idea of how calling this mail. i try to hava page with two columns, one for links and one for the content of the links. something like that : index.php : --------------------- | | | |links | main | | | | | | | | | | --------------------- it contains <div id="links"> <?php include ("./links.php");?></div> <div id="main"> <?php include ("./$main"); ?> </div> with the appropriate css style $main corresponds to "link1.php" or "link2.php" index.php is the only page visible and its content changes when a link is selected. links.php corresponds to : <a href="./link1.php"> link 1</a></p> <a href="./link2.php"> link 2</a></p> how can I do this ? Thanks in advance.