Can someone help me to Spot the problems and correct it.

#include <cstdlib>
#include <iostream>
#define NUM 10
 
using namespace std;
 
char city[]="Penang";
int count;
int pgm_var = 7;
void do_var_fun();

int main(int argc, char *argv[])
{
    int abc;
    count = NUM;
    abc = 5;
    do_var_fun();
    cout<<abc<<" "<<count<<" "<<pgm_var<< " " <<xyz;
    system("PAUSE");
    return EXIT_SUCCESS;
}
 

 
void do_var_fun()
{
    char xyz ='A';
    xyz = 'b';
    cout <<xyz<<" "<<pgm_var <<" " <<abc<< " "<<city;
    return;
}