var imagenumber = 6 ; //Anzahl der Grafiken
var randomnumber = Math.random() ;
var rand1 = Math.round( (imagenumber-1) * randomnumber) + 1 ;

anzeige = new Array

anzeige[1]  = '<a href="http://klick.affiliwelt.net/klick.php?bannerid=18313&pid=11297&prid=289" target="_blank">'
            + '<img src="http://view-affiliwelt.net/b18313_11297_289.gif" '
            + 'alt="www.affiliwelt.net" width="728" height="90"  border="0" ></a>'
            
anzeige[2]  = '<img src="http://ad.zanox.com/ppv/?16286998C1619658141" align="bottom" border="0" hspace="0">'
            + '<a href="http://ad.zanox.com/ppc/?16286998C1619658141T&ULP=[[XXX]]" target="_blank">'
            + '<img src="http://momox.s3.amazonaws.com/728x90_Momox-books.gif" align="bottom" border="0" hspace="0" alt="Momox-Books.de - Einfach verkaufen."></a>'
            
anzeige[3]  = '<a href="http://partners.webmasterplan.com/click.asp?ref=5503&site=1300&type=b66&bnb=66" target="_blank">'
            + '<img src="http://banners.webmasterplan.com/view.asp?ref=5503&site=1300&b=66" '
            + 'alt="Abebooks.de - 110 Mio. neue, gebrauchte und antiquarische Bücher" border="0" width="728" height="90" /></a>'
            
anzeige[4]  = '<a href="http://klick.affiliwelt.net/klick.php?bannerid=36561&pid=11297&prid=2216" target="_blank">'
            + '<img src="http://view-affiliwelt.net/b36561_11297_2216.gif" '
            + 'alt="Die gro&szlig;e Halloween-Verlosung" border="0" width="728" height="90"></a>'

anzeige[5]  = '<a href="http://partners.webmasterplan.com/click.asp?ref=5503&site=4644&type=b119&bnb=119" target="_blank">'
            + '<img src="http://banners.webmasterplan.com/view.asp?ref=5503&site=4644&b=119" '
            + 'alt="HEKTICKET.de - Tickets zu besten Konditionen!" border="0" width="728" height="90" /></a>'
            
anzeige[6]  = '<a href="http://partners.webmasterplan.com/click.asp?ref=5503&site=4586&type=b89&bnb=89" target="_blank">'
            + '<img src="http://banners.webmasterplan.com/view.asp?ref=5503&site=4586&b=89" '
            + 'alt="maxdome - Deutschlands größte Online-Videothek" border="0" width="728" height="90" /></a>'
            
anzeige[7]  = '<a http://partners.webmasterplan.com/click.asp?ref=5503&site=1879&type=b82&bnb=82" target="_blank">'
            + '<img src="http://banners.webmasterplan.com/view.asp?ref=5503&site=1879&b=82" '
            + 'alt="www.tchibo.de" border="0" width="728" height="90" /></a>'
            
anzeige[8]  = '<a href="http://partners.webmasterplan.com/click.asp?ref=5503&site=2488&type=b512&bnb=512" target="_blank">'
            + '<img src="http://banners.webmasterplan.com/view.asp?ref=5503&site=2488&b=512" '
            + 'alt="Über 3000 Zeitschriften beim Deutsche Post Leserservice" border="0" width="728" height="90" /></a>'
            
var einblendung = anzeige[rand1];

document.write(einblendung);