javascript - jQuery Problems with removing event handler with .off() -

i have tried remove event handler .off(), not work.

i want remove event handlers 1 input:

<input type="file" id="file_upload" name="file_upload" size="50" /> 

here have tried:

$('#form').on('keyup change', ':input', function() {     registerchange(); }); $('#form input[name=file_upload]').off(); $('#file_upload').off(); 

you can use not selector file upload button

$('#form').on('keyup change', 'input:not([name=file_upload])',  function() {    registerchange($(this).val());  });    function registerchange(value) {    // notice typing upload textbox not log console    console.log(value);  }    $('#form').on('click', 'input[name=file_upload]', function () {    alert('in click event handler, removing myself');    // here how can remove event handler    $('#form').off('click', 'input[name=file_upload]');  });

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>  <form id="form">    <input type="text" />    <input type="text" />    <!-- changeing textbox demo -->    <input type="text" id="file_upload" name="file_upload" size="50" value="choose file" />  </form>

open console window (ctrl+shift+j in chrome) , type of text boxes. notice how first 2 text boxes write console. note last text box defines on click handler removes it, why alert shows once.