working on a program from Cocoa Programming For Mac OS X Third Edition by Aaron Hillegass. i am on, i believe the third program from the book. One thing i find confusing is that the second program, I think it is called lottery, created an executable that prints numbers at certain indexes: Code: The number at index 0 is 0 The number at index 1 is 3 ... etc. I have the files for the book in my Home directory in a folder called Development. In the Development folder i have two folders, guiprograms and a folder called toolprograms. The first lottery program i put in the toolprograms folder. and i now have an executable file within a folder called lottery which is in the toolprograms folder. In the book it talks about: "In the toolbar, you will see a pop-up for the Active Build Configuration. There are two choices: Debug and Release. While working on your application, you will always want to be in Debug. ..." the book goes on to say that if you want your program to be universal use a Release Build. I built and ran the program before i could find the debug in the toolbar that the book was talking about. So i had two executables, one in a release folder and one in a debug folder. When i started working on the third program, when i went to build and run the program i got an error message: my x-code window says, symbol(s) not found. And it seems like the second program lottery's debug executable is gone. Some questions i have are: does my executable have a file extension? does the author want the second lottery program to be an extension of the first program? like in the book we just edited lottery.m adding some to the file and deleting some from the file. If i alter a file in x-code is the executable stay the same? One thing i did was go into terminal and compile the program from the command line and it compiled. What am i doing wrong? Any help would be appreciated. one thing i thought about doing was throw out all the files, and rewrite them. I am a little confused on the directory structure, like in the book they show a screenshot of typing the name of a file called LotteryEntry.m under location they have ~/Documents/Projects/Cocoa/lottery is the last entry in the path a name of a file or a directory? again any help would be appreciated. question is there a way in x-code to see where this error is or do to the nature of the error is this not possible in this example. There is other stuff written in the error from x-code.