// JavaScript Document
function myTopnav(id,n){
				var c=document.getElementById(id),
				div=c.getElementsByTagName("div"),
				index=0,//市长之窗 0 ，江阴概况 1 ，以此类推
				Each=function(arr,fun){for(var i=0,len=arr.length;i<len;i++)fun(arr[i],i)},
				init=function(){c.style.backgroundPosition="0 -"+(index*33+1)+"px"};
				Each(div,function(o,i){
				  o.onmouseover=function(){
					  c.style.backgroundPosition="0 -"+(i*33+1)+"px";
					  }
				  o.onmouseout=function(){
					  c.style.backgroundPosition="0 -"+(index*33+1)+"px";
					  }
				  })
				init();
				}