iOS SDK 4.2 on Snow Leopard & XCode 3.2.6

I am trying to compile a code in XCODE but says it needs iOS SDK 4.2. XCODE installed 4.3. H开发者_高级运维ow do I resolve this problem? Is there a way to upgrade my code to 4.3, or download 4.2? I have Snow Leopard BTW.

Set your base SDK to 4.3 in the Build Settings and you should be able to compile.