macOS Objective-C problem in XCode

HI all,

I just started reading "Programming in Objective-C". Near the beginning, it shows how to run objective-c programs in xcode. I do all that, but when I click "Build and Run," no new window pops up showing the output of my code like it describes in the book! I'm following all the steps and all, but nothing shows up...

Can anyone please help?

Thanks in advance