void commandcode (employees working[], int n)
{
  ifstream infile2;
  string fname2;
  int idnum; //id number
  char ccode; //command code
  double payr; //pay rate
  char jobst; // job status
  int i;

  cout << "Enter name of second data file" << endl;
  cin >> fname2;
  infile2.open(fname2.c_str());

  infile2 >> idnum;
  infile2 >> ccode;
  while (!infile2.eof())
    {
      search (working, n, idnum, i);
      if (i == -1)
        {
          cout << "ID# " << idnum << "is invalid" << endl;
          infile2.ignore(80, '\n');
        }
      if (ccode == 'P')
        {
          infile2 >> payr;
          working[i].hoursr = payr;
          cout << "ID# " << working[i].id << " hourly pay rate changed to " << working[i].hoursr << endl;
        }
      if (ccode == 'S')
        {
          infile2 >> jobst;
          working[i].jobs = jobst;
          cout << "ID# " << working[i].id << " status changed to " << working[i].jobs << endl;
        }
      if (ccode != 'S' && ccode != 'P')
        {
          cout << "Incorrect command letter used: " << ccode << endl;
          infile2.ignore(80, '\n');
        }

    }
  infile2 >> idnum;
  infile2 >> ccode;
}


int search (employees working[], int n, int idnum, int i)
{
  for (i = 0; i < n; i++)
    {
      if(idnum == working[i].id)
        {
          cout << i;
          return i;
        }
    }
  i = -1;
  return i;
}

.
.
.
    int i; // i is unitialized, so its value is undefined
.
.
.
    search (working, n, idnum, i); // the value of i is still undefined after this
.
.
.
    working[i].hoursr = payr;     // Addressing what element? undefined behavior
.
.
.
    working[i].jobs = jobst;      // Addressing what element? undefined behavior
.

int search(employees working[], int n, int idnum, int i) // <--- i is passed by value
{
        //Nothing in this function will affect the value if i back in the calling function
}