jQuery AJAX loads twice - php

Question

I'm programming a site, and I've got a problem.
I have the following jQuery code:
$('input[type="text"][name="appLink"]').keyup(function() {
var iTunesURL = $(this).val();
var iTunesAppID = $('input[name="iTunesAppID"]').val();
$.ajax({
type: 'POST',
url: jsonURL,
dataType: 'json',
cache: false,
timeout: 20000,
data: { a: 'checkiTunesURL', iTunesURL: iTunesURL, iTunesAppID: iTunesAppID },
success: function(data) {
if (!data.error) {
$('section.submit').fadeOut('slow');
//Modifying Submit Page
setTimeout(function() {
$('input[name="appLink"]').val(data.trackViewUrl);
$('div.appimage > img').attr('src', data.artworkUrl512).attr('alt', data.trackName);
$('div.title > p:nth-child(1)').html(data.trackName);
$('div.title > p:nth-child(2)').html('by '+data.sellerName);
$('span.mod-category').html(data.primaryGenreName);
$('span.mod-size').html(data.fileSizeBytes);
$('span.mod-update').html(data.lastUpdate);
$('select[name="version"]').html(data.verSelect);
$('input[name="iTunesAppID"]').attr('value', data.trackId);
}, 600);
//Showing Submit Page
$('section.submit').delay('600').fadeIn('slow');
} else {
$('.json-response').html(data.message).fadeIn('slow');
}
},
error: function(jqXHR, textStatus, errorThrown) {
//$('.json-response').html('Probléma történt! Kérlek próbáld újra később! (HTTP Error: '+errorThrown+' | Error Message: '+textStatus+')').fadeIn('slow');
$('.json-response').html('Something went wrong! Please check your network connection!').fadeIn('slow');
}
});
});
Sometimes (randomly) the content fades out-in twice.
Could you let me know what's wrong?
Thanks in advance.

Answer 1

I guess the page is dynamically generated from javascript,
If you execute the following function twice, then there be two events since it executes twice,
so a better way is to unbind all previus 'keyup' event and bind it again.
Try this,
$('input[type="text"][name="appLink"]').unbind('keyup').keyup(function() {
});