function an (nr) {
switch (nr) {
case '6':  { document.getElementById('bildinfo').innerHTML=infotext6; break;}
case '5':  { document.getElementById('bildinfo').innerHTML=infotext5; break;}
case '4':  { document.getElementById('bildinfo').innerHTML=infotext4; break;}
case '3':  { document.getElementById('bildinfo').innerHTML=infotext3; break;}
case '2':  { document.getElementById('bildinfo').innerHTML=infotext2; break;}
case '1':  { document.getElementById('bildinfo').innerHTML=infotext1; break;}
default:   {document.getElementById('bildinfo').innerHTML=infotext1;}}
document.getElementById('bildinfo').style.visibility = 'visible'; 
}
function aus () {document.getElementById('bildinfo').style.visibility = 'hidden'; }