function get_slot() {
global $conf;

$len = 7;

$chars = "abcdefghijkmnopqrstuvwxyz0123456789";
$i = 0;

$slot = '' ;
	
while ($i < $len) {
	$num = rand(0, strlen($chars));
	$tmp = substr($chars, $num, 1);
	$slot = $slot . $tmp;
	$i++;
	}
	
return $slot;

}