Hi Jim 

Thanks for posting in the community!

If you're using basic shapes: In order to grab individual objects and prevent the selection area from grabbing more objects than you want I recommend holding down the Control (Ctrl) key then clicking on the objects you want to select. This will select only those shapes and allow you to drag them to the left or right to make room in the middle of your sequence diagram. Note that if you select an object with a line attached to it the line will also move with the object even if you do not select it. You may find it most practical to delete these lines insert your new function in the sequence and then draw new lines to and from this new function to the functions on either side. 

If you're using UML Markup: It is not possible to manually edit the diagram on the canvas. All changes including addition of new functions must be done using the UML Markup dialogue in the left panel. Feel free to take a look at this article on UML Sequence Markup for more help.

Hope this helps!

Micah

Thank you!  Yeah that was pretty much what I did in your first paragraph.  I just figured this product is so damn good (and it is!) that I'm probably missing some secret key sequence or something.  Anyway thank you for the quick reply.

Jim