function changeDisplay(objName) {
  var id = new Array(3);
  id[0]="div";
  id[1]="d";
  id[2]="r";
  var obj;
  for (i=0; i < 3; i++) {
    obj = document.getElementById(id[i] + objName);
    if (obj.style.display == "none")
      eval("obj.style.display='inline'");
    else eval("obj.style.display='none'");
  }
}