Hi, I have a DIM 2400, and at the back there are three outlets to plug in sound cables. I know the Green is for the Speaker System, but of the other two, I don't know which is the Line In and which is the Line Out. None of Dell's papework spell it out. Is the one with the arrow that point inwards the LINE -IN?? It's logical to me, but I want to be sure. I've been fooled by my own logic before. ThanX very much! Mike