//March//
  var indexMar = 1;
  displayMarch(indexMar);

  function March(n) {
    displayMarch(indexMar += n);
    }
  
  function activeMarch(n) {
    displayMarch(indexMar = n);
    }

  function displayMarch(n) {
    var i;
    var allMarch = document.getElementsByClassName("image-container-3");
    var allThumbnails = document.getElementsByClassName("top-img-3");

    if (n > allMarch.length) {
      indexMar = 1;
      }
    if (n < 1) {
      indexMar = allMarch.length;
      }
    for (i = 0; i < allMarch.length; i++) {
      allMarch[i].style.display = "none";
      }
    for (i = 0; i < allThumbnails.length; i++) {
      allThumbnails[i].className = 
        allThumbnails[i].className.replace(" current-top-img", "");
        allThumbnails[i].style.filter = "brightness(50%)";
        }
      if ((indexMar - 1) >= allMarch.length || (indexMar - 1) >= allThumbnails.length)
        return;
      allMarch[indexMar - 1].style.display = "block";
      allThumbnails[indexMar - 1].className += " current-top-img";
      allThumbnails[indexMar - 1].style.filter = "brightness(100%)";
      }