Handle iOS Version for MessageUI.Framework

I am using MessageUI.Framework in m开发者_如何学JAVAy app but the same could not be run on iOS 3.x. Is there any way in which we can check the OS version at compile time. I have tried few solutions(Soln_1 and Soln_2) on web but they did not work.

I have got a solution for the same

#ifdef _USE_OS_4_OR_LATER
   //code for iOS 4.0+
#elseif
   //code for the iOS < 4.0
#endif

This worked for me hope it does for all other as well.