body {text-align: center;margin-top:15px;}

#container{margin:auto; width:950px;height:560px;text-align:left;
border: solid 1px #ff0000;font-weight:bold;font-size:18px;}

#links{float:left;width:250px;height:550px;
border-right:solid 1px red;padding-top:10px;}

#rechts{float:right;width:690px;height:auto;padding-top:25px;text-align:center}

#blok1{width:220px;height:400px;text-align:center;display:block;margin:auto;}
#blok2{width:220px;height:400px;text-align:center;display:none; margin:auto;}
#blok3{width:220px;height:400px;text-align:center;display:none; margin:auto;}

.thumbsize1{width:100px;height:66px;border: solid 2px #ffffff;cursor:pointer;}
.thumbsize2{width:66px;height:100px;border: solid 2px #ffffff;cursor:pointer;}
.thumbsize3{width:66px;height:66px;border: solid 2px #ffffff;cursor:pointer;}

#venster1{margin:auto;width:600px;height:450px;display:block;}
#venster2{margin:auto;width:360px;height:480px;display:none;}
#venster3{margin:auto;width:400px;height:400px;display:none;}