Getting married after entering the US on the Visa Waiver Program (VWP) is not necessarily always as easy as it looks. The USCIS could determine that you entered the country fraudulently (i.e., that you traveled as a visitor when you in fact intended to marry and remain in the US).
Before submitting any application, I would strongly advise you to speak to an attorney who can examine the particulars of your case to determine the best route to follow and if any danger lies ahead.
Edward Weiner
Attorney at Law
E-mail: E.Weiner@immigration-aux-usa.com
Internet Site:
http://www.immigration-aux-usa.com/