In the sequence diagram I am working on, a Lifeline should <<create>> a new object. How do I do that?
The arrow should start from a vertical rectangle without a name and stop at a horizontal rectangle with a name in it and with a lifeline starting from it (stretching south).
thanks,

I found out the answer for myself. I did not know how to delete the question I asked.

Solution: I pushed the Create Message button and placed the arrow from the top of the starting lifeline to the top of the created lifeline. then i draged (by holding the mouse left button in) the arrow down to the place I wanted it, and the level of the created Object followed.