var input = document.getElementById("files");

                    input.addEventListener("change", function (e) {
                        file = e.target.files[0],

                        reader = new FileReader();

                        reader.onload = function () {
                            readPdf(reader.result);
                        }
                        reader.readAsArrayBuffer(file);

                    });


                    function readPdf(buffer) {
                        PDFJS.disableWorker = true;
                        PDFJS.getDocument(buffer).then(function (pdf) {