function selectAllObjects(last_index)
{
	var i;
	for(i = 1; i <= last_index; i++)
	{
		var actual = document.getElementById("selected_item_"+i);
		actual.checked = true;
	}
}

function unselectAllObjects(last_index)
{
	var i;
	for(i = 1; i <= last_index; i++)
	{
		var actual = document.getElementById("selected_item_"+i);
		actual.checked = false;
	}
}