function toEnglish() {
  dds = document.getElementById("english")
  dds.style.display = "block";
  dds = document.getElementById("metric")
  dds.style.display = "none";
}
function toMetric() {
  dds = document.getElementById("metric")
  dds.style.display = "block";
  dds = document.getElementById("english")
  dds.style.display = "none";
}