<?
interface IPerson
{
    public function sayHi($name);
}

class Person implements IPerson
{
	public function __construct()
	{
		
	}
	public function sayHi($name)
	{
		echo "Hi $name how are you?\n";
	}

}
class People implements IPerson
{
	public function __construct()
	{

	}
	public function sayHi($name)
	{
		echo "Hi people how are you?\n";
	}

}

function myfunc(IPerson $person)
{
	echo $person->sayHi("Adnan");
}

$objPerson = new Person();
$objPpl = new People();
myfunc($objPerson);
myfunc($objPpl);

?>