Products with zero quantity showing as Sold Out

Currently using v. 1.3.9f

I am developing a site where all my graphics are custom. I would like to be able have the ability for the users to add products to their carts even when the product quantity is 0. Currently, the "Sold Out" graphic shows when the quantity is 0; I would like to set as default for all products the "Add to Cart" button in this situation. I need to have the quantities for all items set to zero in order to sync. with my integration software running between the store and Quickbooks.

Any help and guidance is greatly appreciated. Please let me know if you need more information from me to provide an awesome response :>)

Happy holidays everyone!

Michael

Check the various settings in admin > config > stock

Thank you Kobra. That did it!