document.getelementbyid().value 不起作用

如何解决document.getelementbyid().value 不起作用

这是我的表单，我的表单中只有几个与我使用的脚本相关的项目，脚本如下

<div class="form-group form-float">
  <div class="form-line">
    <input type="text" class="form-control" name="pembiayaan" id="jumlah" min="1" max="50" value=""
      autocomplete="pembiayaan" autofocus required>
    <label class="form-label">Jumlah Pembiayaan</label>
  </div>
  <div class="help-info">Min. 1,Max. 50 characters</div>
</div>
<div class="form-group form-float">

  <strong>Kegunaan:</strong>
  <select name="kegunaan" id="kegunaan">

    <option value="Modal Kerja" selected>Modal Kerja</option>
    <option value="Investasi">Investasi</option>
    <option value="Konsumtif">Konsumtif</option>



  </select>

</div>
<div class="form-group form-float">
  <div class="form-line">
    <input type="text" class="form-control" name="objek_pembiayaan" min="1" max="50" value=""
      autocomplete="objek_pembiayaan" autofocus required>
    <label class="form-label">Objek Pembiayaan</label>
  </div>
  <div class="help-info">Min. 1,Max. 50 characters</div>
</div>
<div class="form-group form-float">

  <strong>Jenis Pembiayaan:</strong>
  <select name="jenis" id="jenis">

    <option value="Murabahah" selected>Murabahah</option>
    <option value="Qardh" disabled>Qardh</option>
    <option value="Mudharabah" disabled>Mudharabah</option>
    <option value="Musyarakah" disabled>Musyarakah</option>
    <option value="Qardul Hasan" disabled>Qardul Hasan</option>

  </select>

</div>
<div class="form-group form-float">
  <div class="form-line">
    <input type="text" class="form-control" name="jangka_waktu" min="1" max="50" id="waktu" value=""
      autocomplete="jangka_waktu" autofocus required>
    <label class="form-label">Jangka Waktu (Bulan)</label>
  </div>
  <div class="help-info">Min. 1,Max. 50 characters</div>
</div>
<div class="form-group form-float">
  <div class="form-line">
    <input type="text" class="form-control" name="sistem_pembayaran" min="1" max="50" value="Tunai" disabled>
    <label class="form-label">Sistem Pembayaran</label>
  </div>
  <div class="help-info">Min. 1,Max. 50 characters</div>
</div>
<div class="form-group form-float">
  <div class="form-line">
    <input type="text" class="form-control" name="margin" id="margin" min="1" max="50" value="2%" disabled>
    <label class="form-label">Margin</label>
  </div>
  <div class="help-info">Min. 1,Max. 50 characters</div>
</div>

<div class="form-group form-float">
  <div class="form-line">
    <input type="text" class="form-control" name="nisbah" id="nisbah" min="1" max="50" value="">
    <label class="form-label">Nisbah</label>
  </div>
  <div class="help-info">Min. 1,Max. 50 characters</div>
</div>
<div class="form-group form-float">
  <div class="form-line">
    <input type="text" class="form-control" name="total" id="total" min="1" max="50" value="">
    <label class="form-label">Total</label>
  </div>
  <div class="help-info">Min. 1,Max. 50 characters</div>
</div>
<div class="form-group form-float">
  <div class="form-line">
    <input type="text" class="form-control" name="angsuran" id="angsuran" min="1" max="50" value="">
    <label class="form-label">Angsuran per Bulan</label>
  </div>
  <div class="help-info">Min. 1,Max. 50 characters</div>
</div>

这是我的剧本

function hitunghargajual() {
  var jumlah = parseInt(document.getElementById('jumlah').value);
  var waktu = parseInt(document.getElementById('waktu').value);
  var margin = 0.02;
  var nisbah = jumlah * margin;
  var total = jumlah + nisbah;
  var angsuran = total / waktu;

  if (harga != null) {
    document.getElementById('nisbah').value = nisbah;
    document.getElementById('total').value = total;
    document.getElementById('angsuran').value = angsuran;
  }
  else {
    alert("Masukkan Nilai yang Valid!");
  }
}

我已经输入了正确的 id，它怎么不起作用？，我正在尝试做数学但没有任何反应，它没有显示任何东西

解决方法

谢谢大家，我忘了 harga "harga" 到 'jumlah'