An identifier, is not the same as a value. while(choice!=q)?? When choice and q do not even have values. This is the correct code, and if you want explanation, maybe tomorrow or from the other guys cause my eyes are heavy.
using namespace std;
cout«"Enter a number-q to quit: "j
else cout«"No negatives allowed";
Sorry for not using code tags cause I am not on my desktop computer, also, cannot type more......zzzzz............