How to make Login System in php

Create a html Login Form

--create a new file login.php

<form class="form-1" action="login.php" method="post">
<input type="text" name="email" placeholder="Email" required autocomplete="off">
<input type="password" name="pass" placeholder="Password"  required >
<button type="submit" name="submit">
</form>

   -- include class file control.php in login.php
   -- and create a new object $obj and run connect() function for database connection

// add database connection in login.php

<?php
include_once("control.php");
$obj= new Control();
$obj->connect();
?>

// get data using $_POST variable in login.php
<?php
if (isset($_POST['submit'])) {
$email = $_POST['email'];
$pass = $_POST['pass'];
$pass = md5($pass);
$obj->login($email,$pass);
}
?>

// This is My class file control.php

<?php

class Control{
public $localhost ="localhost";
public $root ="root";
public $sdb ="shoppingcart";
protected $connection;

 function connect(){
$connection=mysql_connect($this->localhost,$this->root)or die(mysql_error());
$connection=mysql_select_db($this->sdb)or die(mysql_error());
}

function login($email,$pass){
session_start();
$sql=mysql_query("SELECT * FROM reg WHERE email='$email' AND pass='$pass' LIMIT 1")or die(mysql_error());
$count=mysql_num_rows($sql);
if ($count>0) {
$row=mysql_fetch_array($sql);
$_SESSION['email']=$row['email'];
$_SESSION['pass']=$row['pass'];
header("location:index.php");
exit();
}
}
}
?>