function add_to_comparison_list() {
	var product_listing_form = document.getElementById('product_listing_form').elements;
	var product_ids = '';

	for (var i = 0; i < product_listing_form.length; i++) {
		if (product_listing_form[i].checked) {
			product_ids += product_listing_form[i].value + ',';
		}
	}

	if (product_ids.length > 0) {
		var xhr_callback = {
			success:add_to_comparison_list_success,
			failure:add_to_comparison_list_failure
		}

		YAHOO.util.Connect.asyncRequest('POST', 'ajax_targets/comparison_list.php', xhr_callback, 'product_ids=' + product_ids + '&action=add');
	}
	else {
		alert('No products selected.  Please select products to compare.');
	}

}

function add_to_comparison_list_by_product_id(product_id) {
	if( product_id > 0 ) {
		var xhr_callback = {
			success:add_to_comparison_list_success,
			failure:add_to_comparison_list_failure
		}
		YAHOO.util.Connect.asyncRequest('POST', 'ajax_targets/comparison_list.php', xhr_callback, 'product_ids=' + product_id + '&action=add');
	}
}

function add_to_comparison_list_success(obj) {
	//	alert('Product(s) successfully added to Comparison List');
}

function add_to_comparison_list_failure(obj) {
	alert('Product(s) not added to Comparison List');
}

function remove_from_comparison_list() {
	var comparison_list_form = document.getElementById('comparison_list_form').elements;
	var product_ids = '';

	for (var i = 0; i < comparison_list_form.length; i++) {
		if (comparison_list_form[i].checked) {
			product_ids += comparison_list_form[i].value + ',';
		}
	}

	if (product_ids.length > 0) {	
		var xhr_callback = {
			success:remove_from_comparison_list_success_refresh,
			failure:remove_from_comparison_list_failure
		}

		YAHOO.util.Connect.asyncRequest('POST', 'ajax_targets/comparison_list.php', xhr_callback, 'product_ids=' + product_ids + '&action=remove');
	}
	else {
		alert('No products selected.  Please select products to remove.');
	}
}

function remove_from_comparison_list_by_product_id(product_id) {
	if( product_id > 0 ) {
		var xhr_callback = {
			success:remove_from_comparison_list_success,
			failure:remove_from_comparison_list_failure
		}
		YAHOO.util.Connect.asyncRequest('POST', 'ajax_targets/comparison_list.php', xhr_callback, 'product_ids=' + product_id + '&action=remove');
	}
}

function remove_from_comparison_list_success(obj) {
	//	alert('Product(s) successfully removed from Comparison List');
}

function remove_from_comparison_list_success_refresh(obj) {
	//	alert('Product(s) successfully removed from Comparison List');
	window.location.replace(window.location.href);
}

function remove_from_comparison_list_failure(obj) {
	alert('Product(s) not removed from Comparison List');
}