jQuery(document).ready(function() { 
  var num_refs = 0;               // anzahl der refs
  var ref_pro_screen = 3;         // anzahl der refs pro screen
  var screen = 0;                 // nummer des ref-screens 
  var malus = 0;
  
  jQuery(".reference").animate({ 
          opacity:1.0,
          filter: "alpha(opacity = 100)"
        }, 1000 );
  
  jQuery(".reference").each(function() {
    num_refs++;
  });
  
  if(num_refs%ref_pro_screen == 0)
    malus = 1;
  
  jQuery("#showmoreB").click(function() {
     screen++;
     if(screen <= num_refs/ref_pro_screen - malus) {
       jQuery(".reference").animate({ 
          top:"-=261"
        }, 500 );
     } else {
       screen = 0;
       jQuery(".reference").animate({ 
          top:0
        }, 1500 );
     }
   });
 });