I have, sadly, shown myself to be bad at punctuation. And need further help in mastering it. So this is my question: which one of these sentences is correctly punctuated? "I don't know, what you think you are doing?," said the angry man. OR "I don't know what, you think you are doing?" said the angry man. Should the comma come in after the question mark (or exclamation mark) or should it be left out all together?