Next available flight number

[Continental Sky]

When creating several routes in the same time, in different browser tabs, they all get the same flight number by default; saving the route requires either manually adjusting flight number, or two clicks in the same tab, first to get error message "Flight number has already been assigned", and then second to save under newly generated flight number. It is also possible to tick/untick a day, or change the time, in which case flight number gets updated as well.

It would be more convenient to have option in settings "If flight number is not available, automatically assign next free number", and that's it, save the route under that new number, it's not something that requires special attention.

The similar applies to acquiring used planes, if several planes are open in different tabs, they get the same registration, and then when attempting to lease/purchase, it takes the same correction as above; the same solution could be applied, if registration is already in use, automatically assign next free reg.