php代码弹窗口怎么弄

echo "<script>alert('弹没窗心的形式');</script>";

echo "<script>window.alert('弹没窗心的形式');</script>";

header("Location: popup.html");

echo "<script type="text/javascript">
function popup() {
  var width = 400;
  var height = 400;
  var left = (screen.width - width) / 两;
  var top = (screen.height - height) / 两;
  var windowFeatures = 'width=' + width + ',height=' + height +
                        ',left=' + left + ',top=' + top;
  var newWindow = window.open('popup.html', '', windowFeatures);
  newWindow.focus();
}
</script>";

echo "<button onclick="popup()">翻开自界说弹没窗心</button>";