function showContent1() {
document.getElementById("content1").style.visibility = "visible";
document.getElementById("content2").style.visibility = "hidden";
document.getElementById("content3").style.visibility = "hidden";
document.getElementById("content4").style.visibility = "hidden";
document.getElementById("content5").style.visibility = "hidden";
document.getElementById("content6").style.visibility = "hidden";
document.getElementById("content7").style.visibility = "hidden";
document.getElementById("content8").style.visibility = "hidden";
document.getElementById("content9").style.visibility = "hidden";
document.getElementById("content10").style.visibility = "hidden";
document.getElementById("content11").style.visibility = "hidden";
document.getElementById("content12").style.visibility = "hidden";
document.getElementById("content13").style.visibility = "hidden";
document.getElementById("content14").style.visibility = "hidden";
document.getElementById("content15").style.visibility = "hidden";
}

function showContent2() {
document.getElementById("content1").style.visibility = "hidden";
document.getElementById("content2").style.visibility = "visible";
document.getElementById("content3").style.visibility = "hidden";
document.getElementById("content4").style.visibility = "hidden";
document.getElementById("content5").style.visibility = "hidden";
document.getElementById("content6").style.visibility = "hidden";
document.getElementById("content7").style.visibility = "hidden";
document.getElementById("content8").style.visibility = "hidden";
document.getElementById("content9").style.visibility = "hidden";
document.getElementById("content10").style.visibility = "hidden";
document.getElementById("content11").style.visibility = "hidden";
document.getElementById("content12").style.visibility = "hidden";
document.getElementById("content13").style.visibility = "hidden";
document.getElementById("content14").style.visibility = "hidden";
document.getElementById("content15").style.visibility = "hidden";
}
function showContent3() {
document.getElementById("content1").style.visibility = "hidden";
document.getElementById("content2").style.visibility = "hidden";
document.getElementById("content3").style.visibility = "visible";
document.getElementById("content4").style.visibility = "hidden";
document.getElementById("content5").style.visibility = "hidden";
document.getElementById("content6").style.visibility = "hidden";
document.getElementById("content7").style.visibility = "hidden";
document.getElementById("content8").style.visibility = "hidden";
document.getElementById("content9").style.visibility = "hidden";
document.getElementById("content10").style.visibility = "hidden";
document.getElementById("content11").style.visibility = "hidden";
document.getElementById("content12").style.visibility = "hidden";
document.getElementById("content13").style.visibility = "hidden";
document.getElementById("content14").style.visibility = "hidden";
document.getElementById("content15").style.visibility = "hidden";
}
function showContent4() {
document.getElementById("content1").style.visibility = "hidden";
document.getElementById("content2").style.visibility = "hidden";
document.getElementById("content3").style.visibility = "hidden";
document.getElementById("content4").style.visibility = "visible";
document.getElementById("content5").style.visibility = "hidden";
document.getElementById("content6").style.visibility = "hidden";
document.getElementById("content7").style.visibility = "hidden";
document.getElementById("content8").style.visibility = "hidden";
document.getElementById("content9").style.visibility = "hidden";
document.getElementById("content10").style.visibility = "hidden";
document.getElementById("content11").style.visibility = "hidden";
document.getElementById("content12").style.visibility = "hidden";
document.getElementById("content13").style.visibility = "hidden";
document.getElementById("content14").style.visibility = "hidden";
document.getElementById("content15").style.visibility = "hidden";
}
function showContent5() {
document.getElementById("content1").style.visibility = "hidden";
document.getElementById("content2").style.visibility = "hidden";
document.getElementById("content3").style.visibility = "hidden";
document.getElementById("content4").style.visibility = "hidden";
document.getElementById("content5").style.visibility = "visible";
document.getElementById("content6").style.visibility = "hidden";
document.getElementById("content7").style.visibility = "hidden";
document.getElementById("content8").style.visibility = "hidden";
document.getElementById("content9").style.visibility = "hidden";
document.getElementById("content10").style.visibility = "hidden";
document.getElementById("content11").style.visibility = "hidden";
document.getElementById("content12").style.visibility = "hidden";
document.getElementById("content13").style.visibility = "hidden";
document.getElementById("content14").style.visibility = "hidden";
document.getElementById("content15").style.visibility = "hidden";
}
function showContent6() {
document.getElementById("content1").style.visibility = "hidden";
document.getElementById("content2").style.visibility = "hidden";
document.getElementById("content3").style.visibility = "hidden";
document.getElementById("content4").style.visibility = "hidden";
document.getElementById("content5").style.visibility = "hidden";
document.getElementById("content6").style.visibility = "visible";
document.getElementById("content7").style.visibility = "hidden";
document.getElementById("content8").style.visibility = "hidden";
document.getElementById("content9").style.visibility = "hidden";
document.getElementById("content10").style.visibility = "hidden";
document.getElementById("content11").style.visibility = "hidden";
document.getElementById("content12").style.visibility = "hidden";
document.getElementById("content13").style.visibility = "hidden";
document.getElementById("content14").style.visibility = "hidden";
document.getElementById("content15").style.visibility = "hidden";
}
function showContent7() {
document.getElementById("content1").style.visibility = "hidden";
document.getElementById("content2").style.visibility = "hidden";
document.getElementById("content3").style.visibility = "hidden";
document.getElementById("content4").style.visibility = "hidden";
document.getElementById("content5").style.visibility = "hidden";
document.getElementById("content6").style.visibility = "hidden";
document.getElementById("content7").style.visibility = "visible";
document.getElementById("content8").style.visibility = "hidden";
document.getElementById("content9").style.visibility = "hidden";
document.getElementById("content10").style.visibility = "hidden";
document.getElementById("content11").style.visibility = "hidden";
document.getElementById("content12").style.visibility = "hidden";
document.getElementById("content13").style.visibility = "hidden";
document.getElementById("content14").style.visibility = "hidden";
document.getElementById("content15").style.visibility = "hidden";
}
function showContent8() {
document.getElementById("content1").style.visibility = "hidden";
document.getElementById("content2").style.visibility = "hidden";
document.getElementById("content3").style.visibility = "hidden";
document.getElementById("content4").style.visibility = "hidden";
document.getElementById("content5").style.visibility = "hidden";
document.getElementById("content6").style.visibility = "hidden";
document.getElementById("content7").style.visibility = "hidden";
document.getElementById("content8").style.visibility = "visible";
document.getElementById("content9").style.visibility = "hidden";
document.getElementById("content10").style.visibility = "hidden";
document.getElementById("content11").style.visibility = "hidden";
document.getElementById("content12").style.visibility = "hidden";
document.getElementById("content13").style.visibility = "hidden";
document.getElementById("content14").style.visibility = "hidden";
document.getElementById("content15").style.visibility = "hidden";
}
function showContent9() {
document.getElementById("content1").style.visibility = "hidden";
document.getElementById("content2").style.visibility = "hidden";
document.getElementById("content3").style.visibility = "hidden";
document.getElementById("content4").style.visibility = "hidden";
document.getElementById("content5").style.visibility = "hidden";
document.getElementById("content6").style.visibility = "hidden";
document.getElementById("content7").style.visibility = "hidden";
document.getElementById("content8").style.visibility = "hidden";
document.getElementById("content9").style.visibility = "visible";
document.getElementById("content10").style.visibility = "hidden";
document.getElementById("content11").style.visibility = "hidden";
document.getElementById("content12").style.visibility = "hidden";
document.getElementById("content13").style.visibility = "hidden";
document.getElementById("content14").style.visibility = "hidden";
document.getElementById("content15").style.visibility = "hidden";
}
function showContent10() {
document.getElementById("content1").style.visibility = "hidden";
document.getElementById("content2").style.visibility = "hidden";
document.getElementById("content3").style.visibility = "hidden";
document.getElementById("content4").style.visibility = "hidden";
document.getElementById("content5").style.visibility = "hidden";
document.getElementById("content6").style.visibility = "hidden";
document.getElementById("content7").style.visibility = "hidden";
document.getElementById("content8").style.visibility = "hidden";
document.getElementById("content9").style.visibility = "hidden";
document.getElementById("content10").style.visibility = "visible";
document.getElementById("content11").style.visibility = "hidden";
document.getElementById("content12").style.visibility = "hidden";
document.getElementById("content13").style.visibility = "hidden";
document.getElementById("content14").style.visibility = "hidden";
document.getElementById("content15").style.visibility = "hidden";
}

function showContent11() {
document.getElementById("content1").style.visibility = "hidden";
document.getElementById("content2").style.visibility = "hidden";
document.getElementById("content3").style.visibility = "hidden";
document.getElementById("content4").style.visibility = "hidden";
document.getElementById("content5").style.visibility = "hidden";
document.getElementById("content6").style.visibility = "hidden";
document.getElementById("content7").style.visibility = "hidden";
document.getElementById("content8").style.visibility = "hidden";
document.getElementById("content9").style.visibility = "hidden";
document.getElementById("content10").style.visibility = "hidden";
document.getElementById("content11").style.visibility = "visible";
document.getElementById("content12").style.visibility = "hidden";
document.getElementById("content13").style.visibility = "hidden";
document.getElementById("content14").style.visibility = "hidden";
document.getElementById("content15").style.visibility = "hidden";
}
function showContent12() {
document.getElementById("content1").style.visibility = "hidden";
document.getElementById("content2").style.visibility = "hidden";
document.getElementById("content3").style.visibility = "hidden";
document.getElementById("content4").style.visibility = "hidden";
document.getElementById("content5").style.visibility = "hidden";
document.getElementById("content6").style.visibility = "hidden";
document.getElementById("content7").style.visibility = "hidden";
document.getElementById("content8").style.visibility = "hidden";
document.getElementById("content9").style.visibility = "hidden";
document.getElementById("content10").style.visibility = "hidden";
document.getElementById("content11").style.visibility = "hidden";
document.getElementById("content12").style.visibility = "visible";
document.getElementById("content13").style.visibility = "hidden";
document.getElementById("content14").style.visibility = "hidden";
document.getElementById("content15").style.visibility = "hidden";
}

function showContent13() {
document.getElementById("content1").style.visibility = "hidden";
document.getElementById("content2").style.visibility = "hidden";
document.getElementById("content3").style.visibility = "hidden";
document.getElementById("content4").style.visibility = "hidden";
document.getElementById("content5").style.visibility = "hidden";
document.getElementById("content6").style.visibility = "hidden";
document.getElementById("content7").style.visibility = "hidden";
document.getElementById("content8").style.visibility = "hidden";
document.getElementById("content9").style.visibility = "hidden";
document.getElementById("content10").style.visibility = "hidden";
document.getElementById("content11").style.visibility = "hidden";
document.getElementById("content12").style.visibility = "hidden";
document.getElementById("content13").style.visibility = "visible";
document.getElementById("content14").style.visibility = "hidden";
document.getElementById("content15").style.visibility = "hidden";
}

function showContent14() {
document.getElementById("content1").style.visibility = "hidden";
document.getElementById("content2").style.visibility = "hidden";
document.getElementById("content3").style.visibility = "hidden";
document.getElementById("content4").style.visibility = "hidden";
document.getElementById("content5").style.visibility = "hidden";
document.getElementById("content6").style.visibility = "hidden";
document.getElementById("content7").style.visibility = "hidden";
document.getElementById("content8").style.visibility = "hidden";
document.getElementById("content9").style.visibility = "hidden";
document.getElementById("content10").style.visibility = "hidden";
document.getElementById("content11").style.visibility = "hidden";
document.getElementById("content12").style.visibility = "hidden";
document.getElementById("content13").style.visibility = "hidden";
document.getElementById("content14").style.visibility = "visible";
document.getElementById("content15").style.visibility = "hidden";
}

function showContent15() {
document.getElementById("content1").style.visibility = "hidden";
document.getElementById("content2").style.visibility = "hidden";
document.getElementById("content3").style.visibility = "hidden";
document.getElementById("content4").style.visibility = "hidden";
document.getElementById("content5").style.visibility = "hidden";
document.getElementById("content6").style.visibility = "hidden";
document.getElementById("content7").style.visibility = "hidden";
document.getElementById("content8").style.visibility = "hidden";
document.getElementById("content9").style.visibility = "hidden";
document.getElementById("content10").style.visibility = "hidden";
document.getElementById("content11").style.visibility = "hidden";
document.getElementById("content12").style.visibility = "hidden";
document.getElementById("content13").style.visibility = "hidden";
document.getElementById("content14").style.visibility = "hidden";
document.getElementById("content15").style.visibility = "visible";
}

function loeschen() {
document.getElementById("content1").style.visibility = "hidden";
document.getElementById("content2").style.visibility = "hidden";
document.getElementById("content3").style.visibility = "hidden";
document.getElementById("content4").style.visibility = "hidden";
document.getElementById("content5").style.visibility = "hidden";
document.getElementById("content6").style.visibility = "hidden";
document.getElementById("content7").style.visibility = "hidden";
document.getElementById("content8").style.visibility = "hidden";
document.getElementById("content9").style.visibility = "hidden";
document.getElementById("content10").style.visibility = "hidden";
document.getElementById("content11").style.visibility = "hidden";
document.getElementById("content12").style.visibility = "hidden";
document.getElementById("content13").style.visibility = "hidden";
document.getElementById("content14").style.visibility = "hidden";
document.getElementById("content15").style.visibility = "hidden";
}