Creating a link to the App Store

So I'm creating a free version of my app and I want to place a button that when clicked opens up the full version's page in the app store. But I don't know how to create links in iT2D, and I'm not sure how they would function in-game. Anyone have some experience or advice?

I'm also open to other suggestions (i.e. having it upgrade inside the game instead of simply downloading the full version, but I have no idea how to do that, I assume using inApp purchasing but I'm not sure how that works with iT2D).