Payment gateway implementation in my android application using flex4.5 air.

Hi All,

I have created new android app using flex4.5 air, it look like education use. i would like to implement payment gateway for some portion like image's, audio's,video's,etc.. when user click this feature, user need to pay. what are the steps need to prepare for this implementation.

                                                                            Thanks for your attention,

Jai.