Cara menampikan data otomatis pada field gimana yaa

gan gimana cara nampilin data otomatis yaa, jadi saat jenis layanan di isi , harga ama satuan ikut keisi otomatis, trimakasih

<?php

<div class="form-group">
<label>Jenis Layanan</label>
<select class="form-control" name="layanan_nama" required="required">
<option value="">- Pilih Layanan</option>
	<?php
	     $data = mysqli_query($koneksi,"select * from layanan");
	     while($d=mysqli_fetch_array($data)){
        ?>
<option value="<?php echo $d['layanan_id']; ?>"><?php echo $d['layanan_nama']; ?></option>
        <?php
	     }
	?>

</select>
</div>
<div class="form-group"><label>Harga</label>
<input type="number" class="form-control" name="layanan_harga" readonly="">
</div>
<div class="form-group"><label>Satuan</label>
<input type="number" class="form-control" name="layanan_satuan" readonly="">
</div>

?>