Trying to compile my first widget [solved]

Hello all, I’m trying to compile the first exercice in the book “C++ GUI programming with QT 4” (page 14 and further). For those of you who also tried to copy the code of the manual and compile this, I hope to get help with the following (tons of) errors: allocation of incomplete type ‘QLabel’ allocation of incomplete type ‘QEdit’ allocation of incomplete type ‘QCheckBox’ … no matching member function call to ‘connect’ … unknown type name ‘QHBoxLayout’ I’m using QT5 on a Mac… What’s the problem here? I’ve copied the portions of code literally from the book and it gives these errors… All help very much appreciated! Gabriel