function show_trainingssys() {

    document.getElementById("content_button_trainingssys").style.display = "block";
    document.getElementById("button_op_modelle").style.zIndex = 20;
    document.getElementById("button_training").style.zIndex = 30;
    document.getElementById("button_forschung").style.zIndex = 10;
    document.getElementById("content_button_opmodelle").style.display = "none";
    document.getElementById("content_button_forschung").style.display = "none";
}

function show_opmodelle() {

    document.getElementById("content_button_opmodelle").style.display = "block";
    document.getElementById("button_op_modelle").style.zIndex = 30;
    document.getElementById("button_training").style.zIndex = 20;
    document.getElementById("button_forschung").style.zIndex = 10;
    document.getElementById("content_button_trainingssys").style.display = "none";
    document.getElementById("content_button_forschung").style.display = "none";

}
/* Downloads */

function show_felsenbein() {

    document.getElementById("button_felsenbein").style.zIndex = 20;
    document.getElementById("button_nase").style.zIndex = 10;
    document.getElementById("content_1").style.display = "block";
    document.getElementById("content_2").style.display = "none";
}

function show_nase() {

    document.getElementById("button_felsenbein").style.zIndex = 10;
    document.getElementById("button_nase").style.zIndex = 20;
    document.getElementById("content_1").style.display = "none";
    document.getElementById("content_2").style.display = "block";
}

function show_forschung() {

    document.getElementById("content_button_forschung").style.display = "block";
    document.getElementById("button_forschung").style.zIndex = 30;
    document.getElementById("button_op_modelle").style.zIndex = 20;
    document.getElementById("button_training").style.zIndex = 10;
    document.getElementById("content_button_trainingssys").style.display = "none";
    document.getElementById("content_button_opmodelle").style.display = "none";

}
/* Inhalt Felsenbein & Nase */

function show_content1() {
    document.getElementById("content_4").style.display = "none";
    document.getElementById("content_3").style.display = "none";
    document.getElementById("content_2").style.display = "none";
    document.getElementById("content_1").style.display = "block";
    document.getElementById("bild1").style.display = "block";
    document.getElementById("bild2").style.display = "none";
    document.getElementById("bild2-1").style.display = "none";
    document.getElementById("bild3").style.display = "none";
    document.getElementById("bild4").style.display = "none";
}
function show_content2() {
    document.getElementById("content_4").style.display = "none";
    document.getElementById("content_3").style.display = "none";
    document.getElementById("content_2").style.display = "block";
    document.getElementById("content_1").style.display = "none";
    document.getElementById("bild1").style.display = "none";
    document.getElementById("bild2").style.display = "block";
    document.getElementById("bild3").style.display = "none";
    document.getElementById("bild4").style.display = "none";
}
function show_flash() {
    document.getElementById("bild2").style.display = "none";
    document.getElementById("bild2-1").style.display = "block";
}
function hide_flash() {
    document.getElementById("bild2").style.display = "block";
    document.getElementById("bild2-1").style.display = "none";
}

function show_content3() {
    document.getElementById("content_4").style.display = "none";
    document.getElementById("content_3").style.display = "block";
    document.getElementById("content_2").style.display = "none";
    document.getElementById("content_1").style.display = "none";
    document.getElementById("bild1").style.display = "none";
    document.getElementById("bild2").style.display = "none";
    document.getElementById("bild2-1").style.display = "none";
    document.getElementById("bild3").style.display = "block";
    document.getElementById("bild4").style.display = "none";
}
function show_content4() {
    document.getElementById("content_4").style.display = "block";
    document.getElementById("content_3").style.display = "none";
    document.getElementById("content_2").style.display = "none";
    document.getElementById("content_1").style.display = "none";
    document.getElementById("bild1").style.display = "none";
    document.getElementById("bild2").style.display = "none";
    document.getElementById("bild2-1").style.display = "none"; 
    document.getElementById("bild3").style.display = "none";
    document.getElementById("bild4").style.display = "block";
}
/* Inhalt Presse */

function show_presse1() {
    document.getElementById("content6").style.display = "none";
    document.getElementById("content5").style.display = "none";
    document.getElementById("content4").style.display = "none";
    document.getElementById("content2").style.display = "none";
    document.getElementById("content1").style.display = "block";
    document.getElementById("content3").style.display = "none";
}
function show_presse2() {
    document.getElementById("content6").style.display = "none";
    document.getElementById("content5").style.display = "none";
    document.getElementById("content4").style.display = "none";
    document.getElementById("content2").style.display = "block";
    document.getElementById("content1").style.display = "none";
    document.getElementById("content3").style.display = "none";
}
function show_presse3() {
    document.getElementById("content6").style.display = "none";
    document.getElementById("content5").style.display = "none";
    document.getElementById("content4").style.display = "none";
    document.getElementById("content3").style.display = "block";
    document.getElementById("content2").style.display = "none";
    document.getElementById("content1").style.display = "none";
}
function show_presse4() {
    document.getElementById("content6").style.display = "none";
    document.getElementById("content5").style.display = "none";
    document.getElementById("content4").style.display = "block";
    document.getElementById("content3").style.display = "none";
    document.getElementById("content2").style.display = "none";
    document.getElementById("content1").style.display = "none";
}
function show_presse5() {
    document.getElementById("content6").style.display = "none";
    document.getElementById("content5").style.display = "block";
    document.getElementById("content4").style.display = "none";
    document.getElementById("content3").style.display = "none";
    document.getElementById("content2").style.display = "none";
    document.getElementById("content1").style.display = "none";
}
function show_presse6() {
    document.getElementById("content6").style.display = "block";
    document.getElementById("content5").style.display = "none";
    document.getElementById("content4").style.display = "none";
    document.getElementById("content3").style.display = "none";
    document.getElementById("content2").style.display = "none";
    document.getElementById("content1").style.display = "none";
}