Login.php

<?php
   include("config.php");
   session_start();

   if($_SERVER["REQUEST_METHOD"] == "POST") {
      // username and password sent from form

      $myusername = mysqli_real_escape_string($db,$_POST['login']);
      $mypassword = mysqli_real_escape_string($db,$_POST['password']);

      $sql = "SELECT * FROM userinfo WHERE user_name = '$myusername' and password = '$mypassword'";
      $result = mysqli_query($db,$sql);
      $row = mysqli_fetch_array($result,MYSQLI_ASSOC);
      $active = $row['active'];

      $count = mysqli_num_rows($result);

      // If result matched $myusername and $mypassword, table row must be 1 row

      if($count == 1) {
         session_register("myusername");
         $_SESSION['login_user'] = $myusername;

         header("location: welcome.php");
      }else {
         $error = "Your Login Name or Password is invalid";
      }
   }
?>
<html>
<link href="http://fonts.googleapis.com/css?family=Lobster" rel="stylesheet" type="text/css">
<link rel=StyleSheet href="loginmemory.css">
<head>
  <meta charset="utf-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
  <title>Login Form</title>
<meta name="robots" content="noindex,follow" />
</head>
<body>
  <div class="container">
    <div class="login">
      <h1>Login To The Memory Bank</h1>
      <form method="post" action="">
        <p><input type="text" name="login" value="" placeholder="Username or Email"></p>
        <p><input type="password" name="password" value="" placeholder="Password"></p>
        <p class="remember_me">
          <label>
            <input type="checkbox" name="remember_me" id="remember_me">
            Remember me on this computer
          </label>
        </p>
        <p class="submit"><input type="submit" name="commit" value="Login"></p>
		<span><?php echo $error; ?></span>
      </form>
    </div>