Hi, I am new to programming on Mac. I installed XCode 3.1.3 and was trying to write a C++ program 'Hello World' but I was unable to compile the program. I wrote the program but the 'Build and Go' button is inactive. What am I suppose to do to activate the button or what am I suppose to do to compile a c++ program? Enclosed: Pictures which might help you to understand my problem better. Thanks a lot! Tejas.