function showprev(tphoto , pid)
{
	photo_id = document.getElementById("id_photo");
	photo_number =  document.getElementById("pnumber").innerHTML;

	if(photo_number == 1)
		photo_number = tphoto;
	else
		photo_number = photo_number - 1;

	document.getElementById("pnumber").innerHTML = photo_number;
	photo_id.src="bin/tb.php?c="+pid+"&n="+photo_number+"&z=310";

}

function shownext(tphoto , pid)
{
	photo_id = document.getElementById("id_photo");
	photo_number =  document.getElementById("pnumber").innerHTML;

	if(photo_number == tphoto)
		photo_number = 1;
	else
		photo_number = parseInt(photo_number) + 1;

	document.getElementById("pnumber").innerHTML = photo_number;
	photo_id.src="bin/tb.php?c="+pid+"&n="+photo_number+"&z=310";

}