Login class geeft geen fout

<?PHP
error_reporting(E_ALL);

class UserAuthorization extends MySQLi{
	private $MySQL_HOST="127.0.0.1";
	private $MySQL_USER="root";
	private $MySQL_PASS="";
	private $MySQL_DB  ="cms_db";
	private $ADMIN_MAIL="[email protected]";
	//If you want to recieve emails from all the errors, just edit the value below to true (without quotes!)
	private $mail_admin_on_error=false;
	private $instanceName="Website name for error logging (so the admin knows whats site to look at!)";
	##########################
	private $dbCon;		 ##
	private $RemAdr;        ##
	private $cookieData;	##
	public  $returndata;    ##
	##########################
	
	public function __construct($todo,$data=""){
		$this->RemAdr=md5($_SERVER['REMOTE_ADDR']);
		$this->cookieData = (isset($_COOKIE[$this->RemAdr])) ? $_COOKIE[$this->RemAdr] : "";
		
        parent::__construct($this->MySQL_HOST, $this->MySQL_USER, $this->MySQL_PASS, $this->MySQL_DB);

        if(mysqli_connect_error()){
            $this->LogWrite("[".date("d-m-Y H:i:s")."] -> 'Connection error (".mysqli_connect_errno().") ".mysqli_connect_error())."\r\n";
        }
		
		$this->$todo($data);
	}
	
	public function getdata(){
		return $this->returndata;
	}
	
	private function LogWrite($data){
		if($this->mail_admin_on_error){
			mail($this->ADMIN_MAIL,"Error at webserver [".$this->instanceName."]",$data);
		}
		$fh=fopen("errorLog.txt","a");
		if(!fwrite($fh,$data)){
			$this->returndata="There went something wrong, a mail has been sent to the Administrator.";
			exit();
		}else{
			die("There was an error, and the errorlog could not be updated. The server administrator has been mailed.");
		}
	}
	
	private function executeQuery($sql,$type){
		$sql=parent::escape_string($sql);
		if($type==="get"){
			if($res=parent::query($sql)){
				$rows=parent::field_count($res);
				return $rows;
			}else{
				$this->LogWrite(stripslashes("[".date("d-m-Y H:i:s")."] -> 'Could not execute mysql \"get\" query'\r\n"));
				exit();
				return false;
			}
		}
		
		elseif($type==="send"){
			if($res=parent::query($sql)){
				$this->LogWrite(stripslashes("[".date("d-m-Y H:i:s")."] -> 'Could not execute mysql \"send\" query'\r\n"));
				exit();
				return false;
			}else{
				return true;
			}
		}else{
			$this->LogWrite("[".date("d-m-Y H:i:s")."] -> 'Wrong parameter used on executeQuery function'\r\n");
			exit();
			return false;
		}
	}
	
	//...
	
	private function install($data){
		$sql1="INSERT INTO tblUsers VALUES('Administrator','".md5($data)."','0')";
		$sql2="INSERT INTO tblLoggedIn VALUES('".$this->RemAdr."',1,'".date("Y-m-d H:i:s",strtotime("+3 week"))."')";
		if($this->executeQuery($sql1,"send")&&$this->executeQuery($sql2,"send")){
			setcookie($this->RemAdr,true,time()+604800);
			$this->returndata="Installation succesful!";
			return true;
		}else{
			$this->returndata="Installation failed...";
			return false;
		}
	}
}
?>