EA Extern Variables text message

 
Hi,

When You go F7, you see the input box for the EA showing all the extern variables.

How does one place in those input box EA extern variables a text message to remind me what some of the inputs are for variables/

Like

extern int Period = 1;
extern string Test 1 = daily, 2 = weekly, 3 = monthly;

So I see "Test 1 = daily, 2 = weekly, 3 = monthly" when I go F7 as YELLOW String message, with input demands from the user ?

How is this done ? ( The above does not work, mt4 gives error message) ?
Reason: