jQuery: jcarousel adds empty item in circular mode

We used the jcarousel in our project and also we used the circular mode jCarousel(wrap : ‘circular’) for slider.

We have set 4 item to display in slider. but in the slider we are displaying 3 items so one empty space will display and design is messed up.

So we think we have to fill the empty items. So we tried this code to fill

if( jQuery('#product_carousel').length <= 3 ){ 
tempHtmlData = jQuery('#product_carousel').html(); 
jQuery('#product_carousel').html(tempHtmlData + tempHtmlData); 
}

jQuery('#product_carousel').jcarousel({ 
scroll : 3, 
auto : 4, 
wrap : 'circular' 
});