function getBrick() {
  imagenum = Math.round (Math.random() * 4) + 1;
  if (imagenum == 1){
    var random_image="<img src=img/brick-01.jpg>";
  }
  else if (imagenum == 2){
    var random_image="<img src=img/brick-02.jpg>";
  }
  else if (imagenum == 3){
    var random_image="<img src=img/brick-03.jpg>";
  }
  else if (imagenum == 4){
    var random_image="<img src=img/brick-04.jpg>";
  }
  else if (imagenum == 5){
    var random_image="<img src=img/brick-05.jpg>";
  } 
  document.write(random_image);
}


function getStone() {
  imagenum = Math.round (Math.random() * 3) + 1;
  if (imagenum == 1){
    var random_image="<img src=img/stone-01.jpg>";
  }
  else if (imagenum == 2){
    var random_image="<img src=img/stone-02.jpg>";
  }
  else if (imagenum == 3){
    var random_image="<img src=img/stone-03.jpg>";
  }
  else if (imagenum == 4){
    var random_image="<img src=img/stone-04.jpg>";
  }
  document.write(random_image);
}


function getPavers() {
  imagenum = Math.round (Math.random() * 5) + 1;
  if (imagenum == 1){
    var random_image="<img src=img/pavers-01.jpg>";
  }
  else if (imagenum == 2){
    var random_image="<img src=img/pavers-02.jpg>";
  }
  else if (imagenum == 3){
    var random_image="<img src=img/pavers-03.jpg>";
  }
  else if (imagenum == 4){
    var random_image="<img src=img/pavers-04.jpg>";
  }
  else if (imagenum == 5){
    var random_image="<img src=img/pavers-05.jpg>";
  } 
  else if (imagenum == 6){
    var random_image="<img src=img/pavers-06.jpg>";
  } 
  document.write(random_image);
}