Warning: join() [function.join]: Bad arguments.

[xyn]

Hey, I'm not sure what to do about this error:
Warning: join() [function.join]: Bad arguments. in /home/zroxxco/public_html/habbix/inc/functions.php on line 95

My code:
function deletepost(){
$deleteList = join (',' , $_POST['del']); <Line 95
mysql_query ("DELETE FROM requests WHERE id IN ($deleteList)" );
include("topb.php");
echo ("You have deleted the selected requests.");
include("btm.php");
}

[esukf]

join -- Alias of implode()

http://www.php.net/manual/en/function.implode.php

The second argument need to be an array but you are passing $_POST['del']