Hi! My name is Ricardo and im 15. I decided that i will go to college study computer science, so i think that is better start learning now, and get a feedback about programming. I started reading this book : "Learn to program" by Chris Pine, and i got to admitt, when i first did that thing "Hello World" i really love it, but when i got to this part, things didn't go very good: "Now that you¡Çve gotten everything ready, it¡Çs time to write your first program! Open your text editor, and type the following: puts 1+2 Save your program (yep, that¡Çs a complete program!) as calc.rb. Now run your program by typing ruby calc.rb into your command line. It should put a 3 on your screen." When i opened the command line, and typed calc.rb, it said : "ruby calc.rb is not recognized as an internal or external command operable program or batch file". Please, i need some help :)