var cont = 0;
var calque = new Array();

function ini_permutecalques() {
  for (var i=0; i < ini_permutecalques.arguments.length; i++) {
    calque[i] = findObj(ini_permutecalques.arguments[i]);
    if (i == 0) {
      calque[i].style.display = "block";
    }
  }
}

function permutecalques() {
  prec = cont;
  cont = (cont+1)%calque.length;
  calque[cont].style.display = "block";
  calque[prec].style.display = "none";
}