.prospectus1 a{float:left;width:140px;height:140px;background:url(img/impressions/prospectus/1.png)}
.prospectus1 a:hover{background:url(img/impressions/prospectus/1_thumbs.png)}
.prospectus2 a{float:left;width:140px;height:140px;background:url(img/impressions/prospectus/2.png)}
.prospectus2 a:hover{background:url(img/impressions/prospectus/2_thumbs.png)}
.prospectus3 a{float:left;width:140px;height:140px;background:url(img/impressions/prospectus/3.png)}
.prospectus3 a:hover{background:url(img/impressions/prospectus/3_thumbs.png)}