What is Florida law on giving a child a last name if the farther is not your legal husband?

When you fill out the birth certificate you can give your baby any first, middle, last name you choose. If the child is already here & you want to change his/her last name -go to the courthouse and obtain the proper paperwork and I believe you have to put an ad in your local newspaper for a period of time (that way it gives anybody that would want to protest a chance to).