owl carousel with thumbnails

$(document).ready(function(){
	var sync1=$("#owl_detail");
	var sync2=$("#owl_thumbs");
	var slidesPerPage=4;
	var syncedSecondary=false;
	sync1.owlCarousel({
		items:1,
		//slideSpeed:2000,
		nav:true,
		autoplay:false,
		dots:false,
		loop:false,
		//responsiveRefreshRate:200,
	}).on('changed.owl.carousel',syncPosition);
	sync2.on('initialized.owl.carousel',function(){
		sync2.find(".owl-item").eq(0).addClass("current");
	}).owlCarousel({
		items:slidesPerPage,
		dots:false,
		nav:false,
		loop:false,
		margin:25,
		//smartSpeed:200,
		//slideSpeed:500,
		//slideBy:slidesPerPage,
		//responsiveRefreshRate:100
	}).on('changed.owl.carousel',syncPosition2);
	function syncPosition(el){
		/*
		var count=el.item.count-1;
		var current=Math.round(el.item.index-(el.item.count/2)-.5);
		if(current<0){
			current=count;
		}
		if(current>count){
			current=0;
		}
		*/
		var current=el.item.index;
		sync2.find(".owl-item").removeClass("current").eq(current).addClass("current");
		var onscreen=sync2.find('.owl-item.active').length-1;
		var start=sync2.find('.owl-item.active').first().index();
		var end=sync2.find('.owl-item.active').last().index();
		if(current>end){
			sync2.data('owl.carousel').to(current,100,true);
		}
		if(current<start){
			sync2.data('owl.carousel').to(current-onscreen,100,true);
		}
	}
	function syncPosition2(el){
		if(syncedSecondary){
			var number=el.item.index;
			sync1.data('owl.carousel').to(number,100,true);
		}
	}
	sync2.on("click",".owl-item",function(e){
		e.preventDefault();
		var number=$(this).index();
		sync1.data('owl.carousel').to(number,300,true);
	});
});