function topnav_change(id, over) {
if (over == true) {
file = 'images/' + id + '_h.gif';
} else {
file = 'images/' + id + '.gif';
}
document.getElementById(id).src = file;
}
function buch_change(id, over) {
if (over == true) {
file = 'images/buchbox/' + id + '_h.jpg';
} else {
file = 'images/buchbox/' + id + '.jpg';
}
document.getElementById(id).src = file;
for (var i = 1; i <= 8; i++) {
document.getElementById('buch_' + i + '_desc').style.display = 'none';
}
if (over == true) {
document.getElementById(id + '_desc').style.display = 'block';
} else {
document.getElementById(id + '_desc').style.display = 'none';
}
}

/* Mail decryption */
function decryptThis(s) {
var n=0;
var r="mailto:";
for(var i=0;i<s.length;i++) {
n=s.charCodeAt(i);
if (n>=8364) {n = 128;}
r += String.fromCharCode(n-(2));
}
return r;
}

function doMailto(s) {
location.href=decryptThis(s);
}

function viewdesc(id, over) {
for (var i = 1; i <= 8; i++) {
document.getElementById('buch_desc_foot_' + i).style.display = 'none';
}
if (over == true) {
document.getElementById('buch_desc_' + id).style.display = 'block';
} else {
document.getElementById('buch_desc_' + id).style.display = 'none';
}
}