input select image preview with jquery

ImagePreview.html

<input type="file" name="cover">
<img id="cover_preview" src="">

ImagePreview.js

// 選圖片更新預覽圖
$("input[name=cover]").on("change", function(){
  if (this.files && this.files[0]) {
    var reader = new FileReader();
    reader.onload = function (e) {
      $("#cover_preview").attr('src', e.target.result);
    }
    reader.readAsDataURL(this.files[0]);
  }
});