 <p>(Before the longer discussion: it looks like you're typing <code>myButton</code> one line 2, and <code>eventButton</code> on line 3. Make sure these match!)</p> <p>You're correct in thinking that you're creating a new instance of <code>mainViewController</code>. To get at the one you want, You'll either need to pass a reference to <code>mainViewController</code> into the new view controller when you create it, writing a method like:</p> <pre><code>@synthesize mainViewController; -(void) initWithMainVC:(MainViewController *)mainVC { if ((self = [super init])) { self.mainViewController = mainVC; } return self; } </code></pre> <p>to override <code>init</code>, or, if you've got a reference to <code>mainViewController</code> in your App Delegate, you can get it using:</p> <pre><code>MainViewController *mainVC = [(YourAppDelegate *)[[UIApplication sharedApplication] delegate] mainViewController]; </code></pre> <p>Either way you choose, you'll want to read up on object oriented programming and pointers in objective C. When you call <code>alloc</code>, you're manufacturing a new copy of that class. All copies sit in different chunks of memory, so any new one you make (as in your code above) is actually a totally different entity, like two Priuses, or something like that.</p> <p>A pointer is like a nametag that identifies, or points the way, to that block of memory. In my <code>init</code> code example above, we're attaching a new nametag to a <code>mainViewController</code> instance with the same guts. Same thing with the second line -- we make a new pointer (see the star?) tell it it's going to be pointing to a <code>MainViewController</code> instance, and slap that nametag, or pointer, on to an instance.</p> <p>(The second one is a little more complicated, as you're plucking <code>mainViewController</code> from an object called a singleton, or an object that you can get at from anywhere... read more about those and the App Delegate at <a href="http://cocoawithlove.com/2008/11/singletons-appdelegates-and-top-level.html" rel="nofollow">this post</a> from Cocoa with Love.)</p> <p>Anyway, I get nervous expounding on this stuff on Stack! Check out Apple's <a href="http://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/ObjectiveC/ObjC.pdf" rel="nofollow">Objective C</a> reference for some more of the basics. The sample code on the <a href="http://developer.apple.com/devcenter/ios/index.action" rel="nofollow">iOS Dev Center</a> is really, really good to check out. Download a project that looks nice, or, better yet, just create a project from an Xcode template, and go try to figure out how it's stitched together. Good luck!</p>