Default text in 1 cell when blank - to remain once subsequent text deleted

I have one cell (A9) that I want to read 'Text' for people to know where text should be entered.
I want people to be able to over-write it - and then when text is deleted for 'Text' to appear again.
I also want (if possible) 'Text' to be present when opened - so an auto-open script I guess - meaning when another person opens the document 'Text' is visible.

Ive been searching for a while now - I'm a novice excel user.

Help me Obi-Won youre my only help...

Doesnt seem to work - anytime i try and run it it wants me to create a name...