CRUD Modal Bootstrap edit.php

<?php

    include"koneksi.php";
    $no = 1;
    $data = mysqli_query ($koneksi, " select
                                            id_mahasiswa,
                                            nama,
                                            jenis_kelamin,
                                            telepon,
                                            alamat
                                      from
                                      mahasiswa
                                      where id_mahasiswa = $_POST[id]");
    $row = mysqli_fetch_array ($data);

?>
<form role="form" id="form-edit" method="post" action="update.php">
    <div class="form-group">
        <label>Nama</label>
        <input type="hidden" name="id_mahasiswa" value="<?php echo $row['id_mahasiswa'] ; ?>">
        <input class="form-control" name="nama" value="<?php echo $row['nama'] ; ?>">
        <p style="color:red" id="error_edit_nama"></p>
    </div>
    <div class="form-group">
        <label>Jenis Kelamin</label>
        <div class="radio">
            <label>
                <input type="radio" name="jenis_kelamin" value="Laki-laki"  <?php if($row['jenis_kelamin']=='Laki-laki'){ ; ?> checked <?php } ?>>Laki-laki
            </label>
        </div>
        <div class="radio">
            <label>
                <input type="radio" name="jenis_kelamin" value="Perempuan"  <?php if($row['jenis_kelamin']=='Perempuan'){ ; ?> checked <?php } ?>>Perempuan
            </label>
        </div>
    </div>
    <div class="form-group">
        <label>Telepon</label>
        <input class="form-control" name="telepon"  value="<?php echo $row['telepon'] ; ?>">
        <p style="color:red" id="error_edit_telepon"></p>
    </div>
    <div class="form-group">
        <label>Alamat</label>
        <textarea name="alamat" class="form-control" rows="3"><?php echo $row['alamat'] ; ?></textarea>
        <p style="color:red" id="error_edit_alamat"></p>
    </div>

</form>