$(document).ready(function(){

var patient_count;
var patient_interval;
var old_patient = 0;
var current_patient=0;

$(document).ready(function(){
  patient_count = $("div.patient").size();
  $("div.patient:eq("+current_patient+")").css('top','5px');
  
  patient_interval = setInterval(patient_rotate,10000); //time in milliseconds

});

function patient_rotate() {
  current_patient = (old_patient + 1) % patient_count; //remainder will always equal old_patient until it reaches patient_count - at which point it becomes zero. clock arithmetic
  $("div.patient:eq(" + old_patient + ")").animate({top: -405},"slow", function() {
    $(this).css('top','410px');
    });
  $("div.patient:eq(" + current_patient + ")").show().animate({top: 5},"slow");  
  old_patient = current_patient;
}

});