function doIt(){
  today=new Date();
  jran=today.getTime();
  number = 5

  ia=9301;
  ic=49297;
  im=233280;
  jran = (jran*ia+ic) % im;

  width=770;
  height=50;

  choice = Math.ceil( (jran/(im*1.0)) * number);
  if (choice == 1){
    image="/images/headtop1.jpg";
  }
  if (choice == 2){
    image="/images/headtop2.jpg";
  }
  if (choice == 3){
    image="/images/headtop3.jpg";
  }
  if (choice == 4){
    image="/images/headtop4.jpg";
  }
  if (choice == 5){
    image="/images/headtop5.jpg";
  }
}
doIt();