Ok, I know that the error C2678 is an undefined operand. I have included <iostream> and used namespace std. Yet when I build, the very first error I get is C2678!! and it says '>>' is undefined. Help please!! LOL
Also, you're modifying ID within a for loop that uses it as the terminating condition. This could have unintended consequences.
This:
while(sales >= 0) {
produces undefined behaviour since sales is uninitialized when it reaches that loop. And, if that loop gets entered at all, it will be infinite (well not infinite. It will stop when sales overflows).
- C++ is case-sensitive language (And you have a varialbe "ID" .......);
- cin stands for console input not console output... With cin you control a variable, actually you assign it.