How to set text If data not found

I have a doubt how to set some text like ‘data not found’ when data is not present in the list in combobox. Thanks in advance.

Can you specify:

  1. an empty combo?
  2. you try to find some item in combo, but it is absent?
  3. other case?

And where you want to set this test? As a combo text or it will be something like popup informator?

Sorry for not being not clear, but I want to set some text when a user types something and that is not present in the list.


I want to set text like that one in the image.Is it possible.
If the entered item is absent then it goes blank, there I want to set the text.

Unfortunatelly, there is no approach to achieve such feature.