How to updoad in old browsers (ex Safari 5.1.4)

问题

Trying to upload images to website. encode it to base64. I have this code works in new Chrome/Mozzill/IE11. but it doesn't in Safari 5.1.4 (Windows)

I can see now that FileReader is not available at safari until version 6.0... So any alternatives to this?

<input id="#avatar" type="file" onchange="previewFile()">

This is code

<script>
var img;
function previewFile() {
  var file    = document.querySelector('input[type=file]').files[0];
  var reader  = new FileReader();

  reader.addEventListener("load", function () {
    img = reader.result;
    alert(img)
  }, false);

  if (file) {
    reader.readAsDataURL(file)
  }
}
<...>

</script>

来源：https://stackoverflow.com/questions/38193605/how-to-updoad-in-old-browsers-ex-safari-5-1-4