PHP-OOP - Fatal error: Cannot redeclare class AbstractClass

abstract class BaseValidator{
	protected $msgs = array();
	protected $params = array();
	
	abstract protected function isValid($value);
	
	public function __contruct($_params){
		$this->params = $_params;
	}
	
	public function getMessages(){
		return $this->msgs;
	}
	
}

<?php
require 'BaseValidator.php';

class PasswordValidator extends BaseValidator{
	public function isValid($val=null){
		if($val == null){
			$val = $this->params['value'];
		}
		
		if(strlen($val)<$this->params['minlength']){
			array_push($msgs, 'Password length is too short. Password must be at least 8 characters.');
		}
		
		if(!StringUtil::isAlphabetic($val)){
			array_push($msgs, 'Password can only contain characters in the alphabet. No special characters (@#$%^&*()!) are allowed.');
		}
		
		return count($this->msgs) > 0 ? false : true;
	}
}
?>

$passwordValidationObject = new PasswordValidator(array('minlength'=>6,'value'=>$password,'required'=>true));
	if(!$passwordValidationObject->isValid()){
		echo implode('<br/>',$passwordValidationObject->getMessages());
	}