我想從表單控件類型=“數(shù)字”中獲取一個數(shù)字，將其進(jìn)行比較，然后如果條件確定，則對其進(jìn)行乘法和除法。之后，我想將結(jié)果顯示為<p>標(biāo)簽的內(nèi)容。如何做到這一點？到目前為止，這是我嘗試過的：let amount = document.getElementById(".amount");let marginAmount = document.getElementById(".marginAmount")let submit = document.getElementById(".submit");submit.addEventListener('click', calcAmount);const calcLevel1 = amount * 7 / 100;function calcAmount() {  let userAmount = Number(amount.value);  let level1 = 351;  if (userAmount <= level1) {    marginAmount.textContent = calcLevel1.value;  }}<div class="form">  <label for="points amount">Entrez un montant en points</label>  <input type="number" class="amount-enter" id="amount">  <input type="submit" value="Montant marge additionnelle" id="submit" class="submit-enter"></div><p id="marginAmount" class="enter-margin"></p>