a step is taken, the reset button is made available.
  //
  window.ShowStep = function () {
    document.getElementById("Step"+n).style.visibility = "visible"; n++;
    if (!document.getElementById("Step"+n)) {document.getElementById("step").disabled = true}
    document.getElementById("reset").disabled = false;
  }

  //
  //  Enable the step button and disable the reset button.
  //  Hide the steps.
  //
  window.ResetSteps = function () {
    document.getElementById("step").disabled = false;
    document