布尔函数问题

布尔函数有问题。当我编译程序时，一切运行正常，但是当我输入"no"时，它仍然显示"what can I help you with?"

#include <iostream>
#include <string> //size()
#include <cctype> //isdigit()
using namespace std; //(xxx)xxx-xxxx
bool verification(string yesOrno)
{
    if(yesOrno == "yes")return(true);
    else               return(false);
}
int main()
{
    string yesOrno;
    cout <<"Do you need more helpn";
    cin >> yesOrno;
    if(!verification(yesOrno))cout <<"What can I help you with?n";
    return(0);
}