Problem with streaming Gcode via tx/rx from device to GRBL running on Nano

Here is the part of my code which is handling the communication with GRBL. Waits for ok to send new line and stops when reports on error.


      if (grbl_reply.indexOf("error:") >= 0) {
           while (Serial1.available()) {
            grbl_error += Serial1.read();
           }
        Serial.println(grbl_error);   
        grblReportError();
        return -1;
      }
    }
  }
  grblReportError();    
  return -1;
}