No Upkeep, Low Upkeep, High Upkeep Message

In the top right corner of the screen you can find the upkeep level.

My questions:
1) is it possible to change this message to # Upkeep through triggers? how would this be done?
2) If it isn't possible/easy... Is it possible to create a new upkeep level? Say no, low, medium and high upkeep? If so how would it be done?
3) What do these gameplay constants do? how does the list of their numbers work?
*Upkeep - Gold Tax Rate
*Upkeep - Food Levels
Would they allow me to create custom upkeep levels? If so... how do I change/create the "No/Low/High Upkeep" message that shows up in red letters so it shows when I reach a new upkeep level. How do I modify the top right box message with the upkeep level on it?

Its really easy...In the editor go to advanced:



Like so then click on gameplay constants, then checkmark Use Custom Gameplay Constants, and scroll allllll the way to the bottom, and what you need should be there :D

Heres what you should see:



If you dont understand how to change it from that just post (best smily face ever)

Thanks for the reply. It didn't take me much longer to figure out how to change the upkeep levels using gameplay constants, that was cake

My most important questions are:

- How do I change what the box on the top right corner says?
For example: I want it to say "15% Upkeep" instead of "no upkeep".

- Can I modify the upkeep levels so the RED message that appears say "15% Upkeep"? (I know I can create and format my own text so it looks like the one from the game and center it in the top, I'm just wondering if there's an easier way)

ohh i dont know about that...that dosent sound like somthing you can change though :( But then again what do i know ^_^

EDIT: Go to advanced and click on game interface...i think it might be in there..i didnt have time to check

The game interface solution worked extremely well. I made 5 custom levels of upkeep (0, 5, 10, 15, 20, 25) using gameplay constant, wrote down the text for each of them in the game interface, then I used triggers to create a Ghost, invulnerable, extremely small "food count" unit, that used 5 food (Sentry ward based), and I can switch from one upkeep level to the other by simply making/removing those food count units.

Thanks a lot for your help.