php2ex10 script

<meta charset="utf-8">
<?php
session_start();

    $dbserver   = "localhost";
    $dbuser     = "root";
    $dbpwd      = "";
    $db         = "words";

$link = mysqli_connect($dbserver, $dbuser, $dbpwd, $db);
if(mysqli_connect_errno() > 0){
    echo mysqli_connect_error();
    die;
}
mysqli_query($link,"SET NAMES UTF8");

$sql = "SELECT word,url FROM words";
$result = mysqli_query($link,$sql);
while ($row = mysqli_fetch_array($result,MYSQLI_ASSOC))
  {
      $a[] = $row;
  }
$arr = explode( " ", $_POST['textarea'] );

foreach ($arr as $word){
    foreach ($a as $key){
        if($word == $key['word']){
            $word = "<a href=" . $key['url'] . ">" . $key['word'] . "</a>";
        }
    }
    $words[] = $word;
}

$_SESSION['words'] = $words;
header("Location: /");
?>