Preview image before uploading in jquery

ImagePreview.js

function readURL(input) {
  if (input.files && input.files[0]) {
    var reader = new FileReader();
    reader.onload = function(e) {
      $('#previewHolder').attr('src', e.target.result);
    }

    reader.readAsDataURL(input.files[0]);
  }
}
$("#filePhoto").change(function() {
  readURL(this);
});