Well, you have to hire a patent attorney. Plan on paying a lot of money to get a patent, likely to be $20,000 or more. I would suggest you go to the US Patent Offices website, and look at the patent archives and do a search yourself to save yourself some money. You just put in key words and start looking for where someone has patented the same idea, or somethign super similar.. The website is www.uspto.gov - click over on the search link on the left