(function($) {
$(document).ready( function (){
var counter=0;
var ncounter;
$('.btn_left').click( function(){
ncounter=counter-1;
if($('#dp-item-'+ncounter).html()==null){
ncounter=$('.tc').val()-1;
    $('#dp-item-'+counter).css('display', 'none');   
    $('#dp-item-'+ncounter).css('display','block');    
    counter=$('.tc').val()-1;
} else {

    $('#dp-item-'+counter).css('display', 'none');
    $('#dp-item-'+ncounter).css('display','block');
    counter=ncounter;
}


});

$('.btn_right').click( function(){
ncounter=counter+1;
if($('#dp-item-'+ncounter).html()==null){
    $('#dp-item-'+counter).css('display', 'none');
    $('#dp-item-0').css('display','block');
    counter=0;
} else {
    $('#dp-item-'+counter).css('display', 'none');
    $('#dp-item-'+ncounter).css('display','block');
    counter=ncounter;

}
});
});
})(jQuery);