function museum_an() {
     document.getElementById("bild1").style.visibility  = "hidden";
     document.getElementById("bild3").style.visibility  = "hidden";
     document.getElementById("bild7").style.visibility = "hidden";
     document.getElementById("bild10").style.visibility = "hidden";
     document.getElementById("bild15").style.visibility = "hidden";
     document.getElementById("museum").style.color = "#ff3300";
}
function museum_aus() {
     document.getElementById("bild1").style.visibility = "visible";
     document.getElementById("bild3").style.visibility = "visible";
     document.getElementById("bild7").style.visibility = "visible";
     document.getElementById("bild10").style.visibility = "visible";
     document.getElementById("bild15").style.visibility = "visible";
     document.getElementById("museum").style.color = "#ffffff";
}

function wohnung_an() {
     document.getElementById("wohnung").style.color = "#ff3300";
}
function wohnung_aus() {
     document.getElementById("wohnung").style.color = "#ffffff";
}

function verwaltung_an() {
     document.getElementById("verwaltung").style.color = "#ff3300";
}
function verwaltung_aus() {
     document.getElementById("verwaltung").style.color = "#ffffff";
}
	 
function verkehr_an() {
     document.getElementById("verkehr").style.color = "#ff3300";
}
function verkehr_aus() {
     document.getElementById("verkehr").style.color = "#ffffff";
}

function gewerbe_an() {
     document.getElementById("gewerbe").style.color = "#ff3300";
}
function gewerbe_aus() {
     document.getElementById("gewerbe").style.color = "#ffffff";
}

function staedte_an() {
     document.getElementById("staedte").style.color = "#ff3300";
}
function staedte_aus() {
     document.getElementById("staedte").style.color = "#ffffff";
}
	 
function garten_an() {
     document.getElementById("garten").style.color = "#ff3300";
}
function garten_aus() {
     document.getElementById("garten").style.color = "#ffffff";
}

function ausstellung_an() {
     document.getElementById("ausstellung").style.color = "#ff3300";
}
function ausstellung_aus() {
     document.getElementById("ausstellung").style.color = "#ffffff";
}
	 
function design_an() {
     document.getElementById("design").style.color = "#ff3300";
}
function design_aus() {
     document.getElementById("design").style.color = "#ffffff";
}