how to implement restapi in laravel and its working

My code is given below. I am facing problem. When I want check by username and password. password change every time. so I am unable to give result by email password.

public function login() { 
     $data = Input::all(); 
     print_r($data); 
     $email= $data['email'];

use Request;

public function login(Request $request) { 
$data = $request->all(); 
print_r($data); 
$email= $data['email'];