Cannot read property 'jqBootstrapValidation' - php

Question

I have some errors here in my jQuery. I just want to know what is the problem of this. It can validate my contact form and it says "Message has been sent". I check my email inbox but I have not receive the message.
.
contact_me.js:3 Uncaught TypeError: Cannot read property 'jqBootstrapValidation' of null
(anonymous function) # contact_me.js:3
j # jquery.js:2
k.fireWith # jquery.js:2
m.extend.ready # jquery.js:2
J # jquery.js:2
Here is my code:
<form name="sentMessage" id="contactForm" action="mail/contact_me.php" >
<div class="row">
<div class="col-md-6">
<div class="form-group">
<input type="text" class="form-control" placeholder="Your Name *" id="name" required data-validation-required-message="Please enter your name.">
<p class="help-block text-danger"></p>
</div>
<div class="form-group">
<input type="email" class="form-control" placeholder="Your Email *" id="email" required data-validation-required-message="Please enter your email address.">
<p class="help-block text-danger"></p>
</div>
<div class="form-group">
<input type="tel" class="form-control" placeholder="Your Phone *" id="phone" required data-validation-required-message="Please enter your phone number.">
<p class="help-block text-danger"></p>
</div>
</div>
<div class="col-md-6">
<div class="form-group">
<textarea class="form-control" placeholder="Your Message *" id="message" required data-validation-required-message="Please enter a message."></textarea>
<p class="help-block text-danger"></p>
</div>
</div>
<div class="clearfix"></div>
<div class="col-lg-12 text-center">
<div id="success"></div>
<button type="submit" class="btn btn-xl">Send Message</button>
</div>
</div>
</form>
This is my contact_me.js
$(function() {
$("input,textarea").jqBootstrapValidation(
{
preventSubmit: true,
submitError: function($form, event, errors) {
// additional error messages or events
},
submitSuccess: function($form, event) {
event.preventDefault(); // prevent default submit behaviour
// get values from FORM
var name = $("input#name").val();
var email = $("input#email").val();
var phone = $("input#phone").val();
var message = $("textarea#message").val();
var firstName = name; // For Success/Failure Message
// Check for white space in name for Success/Fail message
if (firstName.indexOf(' ') >= 0) {
firstName = name.split(' ').slice(0, -1).join(' ');
}
$.ajax({
url: "././mail/contact_me.php",
type: "POST",
data: {
name: name,
phone: phone,
email: email,
message: message
},
cache: false,
success: function() {
// Success message
$('#success').html("<div class='alert alert-success'>");
$('#success > .alert-success').html("<button type='button' class='close' data-dismiss='alert' aria-hidden='true'>×")
.append("</button>");
$('#success > .alert-success')
.append("<strong>Your message has been sent. </strong>");
$('#success > .alert-success')
.append('</div>');
//clear all fields
$('#contactForm').trigger("reset");
},
error: function() {
// Fail message
$('#success').html("<div class='alert alert-danger'>");
$('#success > .alert-danger').html("<button type='button' class='close' data-dismiss='alert' aria-hidden='true'>×")
.append("</button>");
$('#success > .alert-danger').append("<strong>Sorry " + firstName + ", it seems that my mail server is not responding. Please try again later!");
$('#success > .alert-danger').append('</div>');
//clear all fields
$('#contactForm').trigger("reset");
},
})
},
filter: function() {
return $(this).is(":visible");
},
});
$("a[data-toggle=\"tab\"]").click(function(e) {
e.preventDefault();
$(this).tab("show");
});
});
/*When clicking on Full hide fail/success boxes */
$('#name').focus(function() {
$('#success').html('');
});
The error begin in the beginning ".jqBootstrapValidation..."