解码64-ATOB空

Question

此脚本正在运行，但是如果没有电子邮件值，它将用ée填充输入。我该如何解决？

document.addEventListener("DOMContentLoaded", function(event) {
  var email = getParameterByName('email');
  document.getElementById('email-assinante').value = "";
  if (email != "") {
    var dec = atob(email);
    document.getElementById('email-assinante').value = dec;
  } else {
    document.getElementById('email-assinante').value = "";
  }
});