this is one of those cases when you want to use malloc(C) or new(C++) to allocate your memory dynamically. this way, when you have LESS than 1000, you're not wasting any space. however, this gets more into pointers and the like so i would suggest doing what stalin said and test for your "fullness" condition BEFORE adding data to the array.
i'm a little drunk right now so "beer" with me...this might do it, but i'm not sure
if (note[999] != NULL)
{
cout<<"too much data!"<<endl;
//<--now do something here to skip it, exit, whatever
}