std::string compare

#include <iostream> 

#define NULL 0
#define MAX_LIMIT 5
//#define MAX_LENGTH 2 

bool ComparePC2S(const char *,const std::string &); 

int main()
{
    const std::string EXIT_STRING="exit"; 

    std::cout<<"Over"<<std::endl;
    char * pChar(NULL);
    pChar=new char[MAX_LIMIT];
    memset(pChar,'\0',MAX_LIMIT);
    std::cin.get(pChar,MAX_LIMIT);
    while(!ComparePC2S(pChar,EXIT_STRING))
    {
        std::cin.sync();//std::cin.ignore(MAX_LENGTH,'\0');
        std::cout << "Please enter your message: ";
        memset(pChar,'\0',MAX_LIMIT);
        std::cin.get(pChar,MAX_LIMIT);
    }
    delete [] pChar;
    return ;
}; 

bool ComparePC2S(const char * pChar,const std::string & str)
{
    const char * pCharTemp=str.c_str();
    if(strlen(pChar)!=strlen(pCharTemp))
        return false;
    int index;
    for(index=;index<std::strlen(pChar);index++)
    {
        if(pChar[index]!=pCharTemp[index])
            return false;
    }
    return true;
};