JS-实现网页上的时钟

JS部分

			window.onload=function(){
				var body=document.getElementsByTagName('body')[0];
				var go=setInterval(function(){
					body.innerHTML='';
					now= new Date();
					year= now.getFullYear();
					month=now.getMonth()+1;
					dat=now.getDate();
					weekday=now.getDay();
					hour=now.getHours();
					minute=now.getMinutes();
					second=now.getSeconds();
					if(weekday==0){
						body.innerHTML='今天是'+year+'年'+month+'月'+dat+'日'+"星期天";
						if(hour>12){
							body.innerHTML=body.innerHTML+'- - -'+(hour-12)+':'+minute+':'+second+'pm'
						}
						else{
							body.innerHTML=body.innerHTML+hour+':'+minute+':'+second+'am'
						}
					}
					else {
						body.innerHTML='今天是'+year+'年'+month+'月'+dat+'日'+"星期"+weekday;
						if(hour>12){
							body.innerHTML=body.innerHTML+'- - -'+(hour-12)+':'+minute+':'+second+'pm'
						}
						else{
							body.innerHTML=body.innerHTML+hour+':'+minute+':'+second+'am'
						}
					}
				},1000)
			}