register class user

<?php
class User{
    var $koneksi;
    var $base_url;
    var $table='tb_user';
    var $col=array("username", "password", "email", "tgl_lahir", "gender", "alamat", "kota", "telp", "paypal_id");

    function __construct($koneksi, $base_url){
        $this->koneksi=$koneksi;
        $this->base_url=$base_url;
    }

    function getColVal(){
        $result="";
        foreach($this->col as $d){
            $result.="$d, ";
        }
        $result=substr($result , 0, -2);
        return $result;
    }

    function getRowVal($data){
        $result="";
        foreach($data as $d){
            $result.="'$d', ";
        }
        $result=substr($result , 0, -2);
        return $result;
    }

    function register(){
        if($_POST['pswd']<>$_POST['copswd']){
            echo("<script LANGUAGE='JavaScript'>
                window.alert('Konfirmasi password tidak sama');
                window.location.href='".$this->base_url."register.php';
            </script>");
            return;
        }
        $row=array($_POST['uname'], md5($_POST['pswd']), $_POST['email'], $_POST['tgll'], $_POST['jeka'], $_POST['alamat'], $_POST['kota'], $_POST['telp'], $_POST['paypal']);
        $kolom=$this->getColVal();
        $baris=$this->getRowVal($row);
        $query="insert into $this->table($kolom) values($baris)";
        $res=mysqli_query($this->koneksi, $query);
        if($res)
        echo("<script LANGUAGE='JavaScript'>
                window.alert('Registrasi berhasil');
                window.location.href='".$this->base_url."register.php';
            </script>");
        else
        echo("<script LANGUAGE='JavaScript'>
                window.alert('Registrasi gagal');
                window.location.href='".$this->base_url."register.php';
            </script>");
    }
}
?>