Is it possible to change the Add to Cart button on the product page to a Buy Now button?

My 'Add to Cart' only gives me the 'Your shopping cart is empty' message. I have read every forum thread concerning this, and tried every suggestion but nothing works.

I need the store to be operable, so I'm ready to switch over to the Buy Now (because it works). But I can't find any place to change that.

Any ideas?

Thank you!