如果安装了IOS 6，则在操作表上显示按钮

I have an actionsheet created, and I want to display the Facebook sharing option. I dont want to use the Composeviewcontroller. My question is: Is it possible to only show the Facebook share option if the user has IOS6 installed? Code snippets would be very useful. I added the social framework and created an actionsheet with some buttons:I have an actionsheet created, and I want to di