var calculatingHeight = false;
function calcHeight() {
	try {
		if (calculatingHeight) return;
		calculatingHeight = true;

		var portfolio = top.document.getElementById('portfolio');
		if(!portfolio) return;
		// force scrollbars temporarily
		portfolio.height = 100;
		// find the height of the internal page
		var the_height = portfolio.contentWindow.document.body.scrollHeight;
		// change the height of the iframe
		portfolio.height = the_height;
		calculatingHeight = false;
	} catch(err) {};
}