Cities in Motion -A rather silly question.

Hi everyone

Well just bought a computer mag and got some game demos with it and am trying out the Cities in Motion demo. Got to the part where you have to place the tram lines, and the tutorial just said to place a circular section of the track to connect the line if you are not building in a loop. (Dont remember the exact words, sorry). Well, I built a line in a straight line from one end of the city to the other, but how am I suppose to place the circular track? I have tried clicking in different ways but all that comes up is a track with two lines in parallel. If I click far enough away from the existing line, the track then placed is circular but if I lead the existing track to the circle, it just changes to the parallel tracks again. I must be missing something here, something that must be quiet obvious but no matter what I try, cant get to join up the ends of the track so that the tram can turn around. Could someone please point out what exactly I need to do here to rectify this problem? I cant save the game so I have just left it paused for the time being while searching for an answer, but cant find anything on it online. And sorry for posting this here, but the pc games help section says it is for problems with pc games, which I assume, means technical problems, but if I made a mistake please move the thread to the appropriate place. And since this is a demo I dont have a manual or anything