I am trying to set the start date and the finish date of a task based on one other task alone.

In other words:

I have task A and task B

Task A starts on 1-Jan-16 and ends on 10-Jan-16

I want task B to start on the same day that task A starts (i.e on 1-Jan) and I want task B to end on the same day that task A ends (i.e on 10-Jan). But I don't want to enter details for task B manually. When I change the start date or duration for task A, I want the details of task B to update automatically.

I tried doing this by setting the predecessor for task B as aSS,aFF. But Project wouldn't let me do this.

Is there a way to address my issue?

Thanks in advance
Best regards
Zam