How to Go Back from Virture Mart Product Details Page to the previous Web Page

[zengfuxu]

I have installed Flexibel Virtuemart Product Carousel in my Joomla 2.5.8 website and load the module in an existing Webpage ("Herbal Products"). When click a product in the Virtuemart Product Carousel, the browser opens the Virture Mart product details page (which is not a real Joomla article) which shows price and description of the product. How can I add a button in this product details page to go back to the webpage ("Herbal Products") where the Virtuemart Product Carousel is located?
Please help. Many thanks!