func say(name:String, msg:String) { println("\(name) say \(msg)") } say("Henry","Hi,Swift") <---- error because missing argument label 'msg' in call I need to use say("Henry",msg:"Hi,Swift") Why ? If I put more than two var in func so that I need to write var name instead of first var when I call this func It's really trouble, and I don't see any explain in iBook Swift tutorial. Can someone give me a help ... Thanks