(function($){
	$.fn.jScroll = function(settings){
		var settings = $.extend();
		return this.each(function(settings){
			var $this = $(this);
			var Bool=false;
			var Scrbody = $this.find(".scrollBody");
			var Scro=Scrbody.find(".scrollBar");
			var Scrp=Scro.find("p");
			var Scrobd=Scrbody.find(".all-list");
			var Scroul=Scrobd.find("ul");
			var letter = Scrbody.prev();
			var Scrp_Height = Scrp.outerHeight()/2;
			var Num2=Scro.outerHeight()-Scrp.outerHeight();
			var offsetX=0;
			var offsetY=0;
			
			Scrp.mousedown(function(e){  
				Bool=true;
			});
			$(document).mouseup(function(){
				Bool=false;
			});
			$(document).mousemove(function(e){
				if(Bool){
					var top = Scro.offset().top;
					var topHeight = top + Scro.outerHeight();
					var value = $this.outerHeight()+$this.offset().top;
					
					if(e.pageY>=top && e.pageY <= topHeight){
						var Num1= e.pageY - value - 70;
						var y = Num1 - Scrp_Height;
					}
					if(y<=1){
						Scrll(0);
						Scrp.css("top",1);
					}else if(y>=Num2){
						Scrp.css("top",Num2);
						Scrll(Num2);
					}else{
						Scrll(y);
					}
				}
			});
			function Scrll(y){
				Scrp.css("top",y);
				Scroul.css("margin-top",-(y/(Scro.outerHeight()-Scrp.outerHeight()))*(Scroul.outerHeight()-Scrobd.height()));
			}
			function wheel(e){
				var Distance=Num2*0.1;
				var evt = e || window.event;
				var wheelDelta = evt.wheelDelta || evt.detail;
				
				//火狐浏览器禁止页面滚动轴滚动
				if (navigator.userAgent.toLowerCase().indexOf('firefox')>=0){
					if (e.preventDefault)
					e.preventDefault();
					e.returnValue = false;
				}
				
				if(wheelDelta == -120 || wheelDelta == 3){
					var Distances=Scrp.position().top+Distance;
					if(Distances>=Num2){
						Scrp.css("top",Num2);
						Scrll(Num2);
					}else{
						Scrll(Distances);
					}
					return false;
				}else if (wheelDelta == 120 || wheelDelta == -3){
					var Distances=Scrp.position().top-Distance;
					if(Distances<=1){
						Scrll(0);
						Scrp.css("top",1);
					}else{
						Scrll(Distances);
					}
					return false;
				}   
			}
			
			//测试ie滚动兼容
			var isIE = !!window.ActiveXObject;
			var isIE6 =isIE&&!window.XMLHttpRequest;
            var isIE8=isIE&&!!document.documentMode;
            var isIE7=isIE&&!isIE6&&!isIE8;

			if(isIE8 || isIE7){
				if(document.getElementById("scrollBody").attachEvent)
				document.getElementById("scrollBody").onmousewheel = wheel;
				document.getElementById("scrollBody").attachEvent('DOMMouseScroll',wheel,false);
			}else{
				if(document.getElementById("scrollBody").addEventListener)
				document.getElementById("scrollBody").addEventListener('DOMMouseScroll',wheel,true);
				document.getElementById("scrollBody").onmousewheel=wheel;
			}
						
			function searchClick(letter){
				letter.find("a").hover(function(){
					var index = $(this).index();
					var scrollBody = $(this).parent().next();
					var top = scrollBody.find("li").eq(index).position().top;
					var ulHeight = Scroul.height();
					var mapHeight = Scrobd.height();
					function Scrll2(top){
						Scrp.stop(true,false).animate({"top":top/(ulHeight-mapHeight)*(Scro.outerHeight()-Scrp.outerHeight())},500);
						Scroul.stop(true,false).animate({"margin-top":-top},500);
					}
					if(top<=1){
						Scrp.stop(true,false).animate({"top":1},500);
						Scroul.stop(true,false).animate({"margin-top":0},500);
					}else if(top>=(ulHeight-mapHeight)){
						Scrp.stop(true,false).animate({"top":Num2},500);
						Scroul.stop(true,false).animate({"margin-top":-(ulHeight-mapHeight)},500);
					}else{
						Scrll2(top);
					}
				});
			}
			searchClick(letter);
		});
	}	
})(jQuery);