could you please give me a working solution
There are lots of examples: http://qt-project.org/doc/qt-5/examples-network.html
I'm using Qt 5.3.1, but I don't know about this new syntax you're talking about.
http://qt-project.org/doc/qt-5/qobject.html#connect-4
But this should not be the reason for your problem (it was more a recommendation).