$ad[0]="1.jpg";
$ad[1]="2.jpg";
$ad[2]="3.jpg";

$topadv=-1;
	if (sizeof($ad)!=0)
	{
		if (!isset($_SESSION['pimps_topadv']))
			$_SESSION['pimps_topadv']="";
		$arr=array();
		if ($_SESSION['pimps_topadv']!="*")
			$arr=explode("|",$_SESSION['pimps_topadv']);
		if (sizeof($arr)>sizeof($ad)) 
			$_SESSION['pimps_topadv']="";
		if (sizeof($arr)==sizeof($ad))
		{
			$topadv=array_shift($arr);
			$arr[sizeof($arr)]=$topadv;
		}
		else
		{
			$random=rand(0,sizeof($ad)-1);
			while (in_array($random,$arr))
				$random=rand(0,sizeof($ad)-1);
			$topadv=$random;
			$arr[sizeof($arr)]=$topadv;
		}
		$_SESSION['pimps_topadv']=implode("|",$arr);
	}