Select/Unselect in datable need 2 clicks why?

http://webix.com/snippet/e4697031

I have 2 tables, but I want that only a row in the upper or lower table is selected.
I have described the problem in the code comments.

Thanks,
Mattthias

Unselect within the onSelectChange causes a loop. To prevent it, please use(un)blockEvent() method:

http://webix.com/snippet/20a1bcdf

Perfect,

thanks a lot.