Input Format Rupiah Codeigniter 3

Di tulis di Footer javascript

 var rupiah1 = document.getElementById("rupiah1");

  rupiah1.addEventListener("keyup", function(e) {

    rupiah1.value = convertRupiah(this.value);

  });

terus di view formnya di tambah id

<input type="number" id="rupiah1" name="harga" class="form-control" placeholder="Isi harga (Rp)" required>