clear form values submitting through ajax

You have to do that in the ajax's success callback:

<script type="text/javascript">    $('#send').click(function() {      var form_data = {        name: $('#name').val(),        email: $('#email').val(),        message: $('#message').val()      };      $.ajax({        url: "<?php echo base_url();?>roxcontrol/contact_form",        type: 'POST',        data: form_data,        success: function(msg) {          if (msg == 'YES')            $('#alert-msg').html('<div class="alert alert-success text-center">Your mail has been sent successfully!</div>');            $('#contact')[0].reset(); // <------here you can reset it.          else if (msg == 'NO')            $('#alert-msg').html('<div class="alert alert-danger text-center">Error in sending your message! Please try again later.</div>');          else            $('#alert-msg').html('<div class="alert alert-danger">' + msg + '</div>');        }      });      return false;    });</script>

Also this is not a valid way to have multiple IDs as per this code:

$( '#contact' ).each(function(){   this.reset();});

If you don't have it then just use as i have marked in the success.

Use trigger to reset your form after success event. You are resetting form outside of ajax so on every call it will reset. Try below code

 <script type="text/javascript"> $('#send').click(function() {var form_data = {  name: $('#name').val(),  email: $('#email').val(),  message: $('#message').val()};$.ajax({  url: "<?php echo base_url();?>roxcontrol/contact_form",  type: 'POST',  data: form_data,  success: function(msg) {    if (msg == 'YES')    {      $('#alert-msg').html('<div class="alert alert-success text-center">Your mail has been sent successfully!</div>');        $( '#contact' ).trigger("reset");     }    else if (msg == 'NO')      $('#alert-msg').html('<div class="alert alert-danger text-center">Error in sending your message! Please try again later.</div>');    else      $('#alert-msg').html('<div class="alert alert-danger">' + msg + '</div>');  }});return false;});</script>

Use this :

$('#Your_form_id').trigger('reset');