function zeigemenus1() {
document.getElementById("spalte2").style.visibility = "hidden";
document.getElementById("spalte1").style.visibility = "visible";
}

function zeigemenus2() {
document.getElementById("spalte1").style.visibility = "hidden";
document.getElementById("spalte2").style.visibility = "visible";
}

function loeschen() {
document.getElementById("spalte1").style.visibility = "hidden";
document.getElementById("spalte2").style.visibility = "hidden";
}

function anzeigen(element) {
 if (document.getElementById(element).style.display == "none") {
  document.getElementById(element).style.display = "block";
 } else {
  document.getElementById(element).style.display = "none"; 
 }
}