function mehr(welches) {
  var mehrwelches = "mehr" + welches;
  var wenigerwelches = "weniger" + welches;
  document.getElementById(welches).style.display = "block";
  document.getElementById(mehrwelches).style.display = "none";
  document.getElementById(wenigerwelches).style.display = "inline";
}

function weniger(welches) {
  var mehrwelches = "mehr" + welches;
  var wenigerwelches = "weniger" + welches;
  document.getElementById(welches).style.display = "none";
  document.getElementById(mehrwelches).style.display = "inline";
  document.getElementById(wenigerwelches).style.display = "none";
}