function updateRentalPeriod( which, type, id )
{
	var url    = "ajax/ajax.update-rental-period.php";
	var div    = "debug_div";
	
	var params = "type=" + type + "&id=" + id + "&which=" + which.value;
	
	var ajax   = new Ajax.Updater(
		div,
		url,
		{
			parameters: params,
			evalScripts: true,
			method: 'post'
		}
	);
}