i would like to build an iphone app which at some point might pop up a message box asking the user to whether would like to subscribe the particular service provided..if user click yes, it will automatically send out a shortcode for example without prompting user to key in anything...

anyone know how can it be implemented?

i've found an app called isms..but dun have any documentation of it..it used its private api..so i wonder is there any private api available on net? anyone know?

actually that impossible automatic sending sms from iphone . but u can make a link to sms app from iphone .