dynamic tables

<script>
    var urut = 1;
    function addRows() {
        var prm = prompt("Mau tambah berapa baris ?", 1);
        for(var i = 1; i <= prm; i++){
        var table = document.getElementById('detail-anggaran');
        var lengthRow = document.getElementById('detail-anggaran').rows.length;
        var row = table.insertRow(lengthRow);
        var nomorUrut = row.insertCell(0);
        nomorUrut.innerHTML = ++urut;
        var uraian = row.insertCell(1);
        uraian.innerHTML = '<input type="text" name="uraian[]" class="form-control" required/>';
        var volume = row.insertCell(2);
        volume.innerHTML = '<input type="number" name="volume[]" class="form-control" required/>';
        var satuan = row.insertCell(3);
        satuan.innerHTML = '<select class="form-control" name="satuan[]" required>' +
                '<option value="paket">Paket</option>' +
                '<option value="personel">Personel</option>' +
                '<option value="buku">Buku</option>' +
                '<option value="bulan">Bulan</option>' +
                '<option value="tahun">Tahun</option>' +
                '</select>';

        var hrgSatuan = row.insertCell(4);
        hrgSatuan.innerHTML = '<input type="number" name="harga-satuan[]" required class="form-control" />';
        var pengeluaran = row.insertCell(5);
        pengeluaran.innerHTML = '<input type="number" name="pengeluaran[]" required class="form-control" />';
    }
    }

</script>