SQL

1
<html>
<body>

<?php
  $show = 1;
  if(!empty($_GET['username']) and !empty($_GET['password'])) {
    $user = $_GET['username'];
    $pass = $_GET['password'];

    mysql_connect("localhost", "admin", "admin");
    mysql_select_db("db");
    $result = mysql_query("SELECT * FROM users WHERE username='".$user."'
      AND password='".$pass."';");
    $row = mysql_fetch_row($result);
    if($row) {
      echo "Welcome user: ".$user;
      $show = 0;
    }
  }
?>

<?php if($show) { ?>
<form action="#">
  Username: <input type="text" name="username" /><br />
  Password : <input type="password" name="password" /><br />
</form>
</body>
</html>
<?php } ?>
1