请些一段兼容IE的JS弹窗代码，蓝色风格

好的，以下是一段兼容IE的JS弹窗代码，蓝色风格：

function showAlert() {
  var alertBox = document.createElement("div");
  alertBox.style.position = "fixed";
  alertBox.style.top = "50%";
  alertBox.style.left = "50%";
  alertBox.style.transform = "translate(-50%, -50%)";
  alertBox.style.backgroundColor = "#0070c0";
  alertBox.style.color = "#fff";
  alertBox.style.padding = "20px";
  alertBox.style.borderRadius = "5px";
  alertBox.style.boxShadow = "0 0 10px rgba(0,0,0,.3)";

  var message = document.createElement("p");
  message.innerText = "这是一条弹窗消息！";

  var closeButton = document.createElement("button");
  closeButton.innerText = "关闭";
  closeButton.style.backgroundColor = "#fff";
  closeButton.style.color = "#0070c0";
  closeButton.style.padding = "5px 10px";
  closeButton.style.border = "none";
  closeButton.style.borderRadius = "5px";
  closeButton.style.cursor = "pointer";
  closeButton.onclick = function() {
    document.body.removeChild(alertBox);
  };

  alertBox.appendChild(message);
  alertBox.appendChild(closeButton);

  document.body.appendChild(alertBox);
}

你可以将它放在 HTML 的 head 标签内，然后在需要弹窗的地方调用 showAlert() 函数即可。