function showRegion(globalregion) {
  if (globalregion == "group_a") {
    document.getElementById("group_a").style.display="block";
    document.getElementById("group_b").style.display="none";
  }
  if (globalregion == "group_b") {
    document.getElementById("group_a").style.display="none";
    document.getElementById("group_b").style.display="block";
  }
}