Using cout to display function return output

[x-ice]

#include <iostream>
#include <string>

using namespace std;

string clientName = "Dan";

void main(void)
{
	cout << getClientName() << endl; //This is Line 10
}

string getClientName()
{
     return clientName;
}

When i use this code I receive an error on line 10, the error is 'error C3861: 'getClientName': identifier not found'