function ShowReg(op) {
  document.getElementById('Principles').style.display='none';
  document.getElementById('Partners').style.display='none';
  document.getElementById('Directors').style.display='none';

  if (op == 1) {
    document.getElementById('Principles').style.display="block";
  }
  if (op == 2) {
    document.getElementById('Partners').style.display="block";
  }
  if (op == 3) {
    document.getElementById('Partners').style.display="block";
  }
  if (op == 4) {
    document.getElementById('Directors').style.display="block";
  }
}