fileupload validation by java script

Question

i want to restrict pdf file on file upload control i want java script for that i want to apply that java script in file upload event

Answer 1

You can check the file name on submit.

"hook to the <form>'s onsubmit with whatever method" {
  filename = theFileElement.value;
  if (!/\.pdf$/i.test(filename)) {
    alert("error");
    return false;
  }
  return true;
}

Note that this only checks if the file has an extension of .pdf. It does not (and cannot) check whether the file is really a just PDF or actually a nasty virus. Moreover, client side Javascript can easily be bypassed, so you should perform the check again on the server side.