Visual C++ :: Binary To Decimal Converter?

I'm trying to figure out why the binary to decimal part is not working correctly when the binary value finishes with a 1. In those cases, the decimal value shown in one unit smaller than it should be.

Code:

#include <iostream>
#include <cstdio>
#include <cstdlib>
using namespace std;
void Binary_to_Decimal(), Decimal_to_Binary(); //prototype for the 2 functions that contain the converters
int main() //the menu {
int a_Choice;
cout << "Enter 1 - for binary to decimal" << endl;
cout << "Enter 2 - for decimal to binary" << endl;

[code]....