Cycle Jquery UI Tab on "previous" and "next" button

I am using Jquery UI Tabs for my website.

<script type='text/javascript'>
//<![CDATA[ 
jQuery(window).load(function(){
jQuery('#myTabs').tabs({ fx: { opacity: 'toggle' }});

jQuery('.next-product').click(function(){ 
var jQuerytabs = jQuery('#myTabs').tabs();
var selected = jQuerytabs.tabs('option', 'selected');
jQuerytabs.tabs('select', selected+1);
});

jQuery('.previous-product').click(function(){ 
var jQuerytabs = jQuery('#myTabs').tabs();
var selected = jQuerytabs.tabs('option', 'selected');
jQuerytabs.tabs('select', selected-1);
});

As you can see that i have been using the previous next button to move from one tab to another. My question is "When i click on next and if the last tab is open then automatically the first tab should get open, and similarly When i click on previous and if the first tab is open then automatically the last tab should get open"

Please help me out, i am stuck from over 3 days now and no solution. I have searched a lot on net but no solution for this.

Solution

You can count the number of .ui-tabs-panel elements.

jQuery(window).load(function() {

    var $tabs = jQuery('#myTabs');

    $tabs.tabs({
        fx: {
            opacity: 'toggle'
        }
    });

    var amount = $tabs.find('.ui-tabs-panel').length;

    jQuery('.next-product').click(function() {
        var selected = $tabs.tabs('option', 'selected');
        $tabs.tabs('select', selected + 1 === amount ? 0 : selected + 1);
    });

    jQuery('.previous-product').click(function() {
        var selected = $tabs.tabs('option', 'selected');
        $tabs.tabs('select', selected === 0 ? amount - 1 : selected - 1);
    });

});

DEMO

Notes:

select your tab element already and re-use the selector var $tabs = jQuery('#myTabs');, it'll be more efficient
no need to re-call .tabs() on your click handlers