<?php
if(isSet($_GET["id"])){
  $id = $_GET["id"];
  switch($id){
    case 1: $fileName = "./art1.html";break;
    case 2: $fileName = "./art2.html";break;
    case 3: $fileName = "./art3.html";break;
    default: die("error");
  }
  if(($str = file_get_contents($fileName)) === false){
    echo "error";
  }
  else{
    echo $str;
  }
}
else{
  echo "error";
}
?>
