<?php
class Zend_Auth_Adapter_simpleAuth implements Zend_Auth_Adapter_Interface {
	public function __construct($username,$password);
		$this->username=$username;
		$this->password=$password;
	}
	public function authenticate(){
		if($username=="admin" && $password="q12we34r"){
			return New Zend_Auth_Result(Zend_Auth_Result::SUCCESS,$this->username,array());
		}else{
			return new Zend_Auth_Result(Zend_Auth_Result::FAILURE,null,array("Authentication Unsuccessful"));
			}

	}
}
Error:
Fatal error: Non-abstract method Zend_Auth_Adapter_simpleAuth::__construct() must contain body in C:\xampp\htdocs\ZFApp\library\Zend\Auth\Adapter\simpleAuth.php on line 3