Your Theme is enqueueing jQuery 1.7.2:
<script type="text/javascript" src="http://dayfun.ir/wp-content/themes/Sparks/lib/js/jquery.min.1.7.2.js"></script>
And WordPress is enqueueing jQuery 1.8.3:
<script type="text/javascript" src="http://dayfun.ir/wp-includes/js/jquery/jquery.js?ver=1.8.3"></script>
See also, Frank’s answer regarding jQuery no-conflict mode.
Edit
WordPress bundles a version of jQuery. You will inevitably encounter problems if your Theme (or a Plugin) enqueues a separate version of jQuery – whether by enqueueing that separate jQuery version along side the WordPress-bundled version, or else by deregistering the core-bundled version, and enqueueing a custom version.
Don’t register a custom version of jQuery via your Theme or any Plugins. If you need to use jQuery, just use the core-bundled version, via:
wp_enqueue_script( 'jquery' );