Right now the norm is that to add a new inventory item, you can only do that by its seperate form.
What if you want to add it while in the middle of the Invoice entry?
Can we have something like a popup or a tab, that will allow us to move to:
purchase items
sale items
inventory items
customers
suppliers
while still working on the Invoice?
Best Regards
That has been discussed many times on this forum and is a possible future development. However, if you are using the Cloud Edition of Manager, you could right click the Inventory Item tab and select “open in a new tab”, after its creation you can then return to the unfinished invoice.
I believe you can do that in the server edition, too, though I am not certain.
Well then I should probably delete the topic.
I swear I really searched for such a topic, and since I couldn’t find one…
Also due to the crisis in Greece right now, I can’t really afford the upgrade yet.
But it is one of my future goals as well! 
You won’t be able to delete the topic, but I will close it.