function addCart(version) {

	var formats = Array('m4v','mp4','3gp');

	var radio_found = '';
	var errmsg = '';

	for (i = 0; i < formats.length; i++) {

		var this_radio_field = formats[i] + '_radio';

		if (document.getElementById(this_radio_field).checked) {

			radio_found = 'yes';
			var format = formats[i];
		}
	}

	if (radio_found == '') {

		alert("You must select a format. Click the red help button if you're not sure which one to pick");
		return false;
	}

	var product = version + '_' + format;
	
	window.location = product_links[product];	
	//alert(product_links[product]);
	
}