JS -文本为空且复选框未勾选时如何停止表单提交？

document.getElementById("myForm").addEventListener("submit", function(event) {
  var textValue = document.getElementById("myText").value;
  var checkboxChecked = document.getElementById("myCheckbox").checked;
  
  if (textValue === "" || !checkboxChecked) {
    event.preventDefault(); // 阻止表单提交
    alert("请填写完整的表单信息");
  }
});

<form id="myForm" novalidate>
  <input type="text" id="myText" required>
  <input type="checkbox" id="myCheckbox" required>
  <input type="submit" value="提交">
</form>