Ok, did some work on it with the help of you guys and guys from other forums, and here's the updated(and heavily fixed) code:


Code:
#include <iostream>
#include <string>

using namespace std;



double dblTrillFunc ( double dblDeciOne , double dblDeciTwo )
   
   {
       //long lnTrillResult;
       
       /* double dblDeciOne(.000000000000000000002);
       double dblDeciTwo(.000000000000000000002); */
       
       double lnTrillResult = ( dblDeciOne * dblDeciTwo );
       
       return(lnTrillResult);
   }


string intro_answer;

string intro_compare = "exit";

long lnBillion = 1000000000;

double z;

int main()
 {
     cout << "Welcome to the Burn-A-Natar 3000! Type in anything to" << endl << \
"continue, or \"exit\" to quit: " << endl;
     
     cin >> intro_answer;
     
     if (intro_answer != intro_compare)
      {   
          do 
             {
              z = z + dblTrillFunc ( .0000000000000000002 , .0000000000000000002 );
              cout << "We're at: " << z << " right now.\n";
             }    
              
          while ( z < lnBillion );
      }
      
      else
      
          {
              cout << "Bye";
              
                  return(0);
          }
      }


That compiles, but with the result of z, it also outputs 4e-blahblah. Anyone know what the reason is?




And I wrote all this in Dev-C++. As you can see, my skills are advancing as I read more of the C++ tutorial at cplusplus.com.