Load more in bootsrapselectpicker

Question

I want to loadmore option on mouse scroll using bootsrap selectpicker, how can i do that?

 $('#rel_id_contact1').bind('scroll', function(){   
        alert("first");
    if($(this).scrollTop() + $(this).innerHeight() +1 >= $(this)[0].scrollHeight){
        alert("asdasd"); return false;
    }
});