function changeImg(){
	  
	   var  tuPian=document.getElementById("tuPian");

	   var i="http://www.dragon-guide.net/pic/mingyan/"+parseInt(Math.random()*390)+".jpg";

       tuPian.src=i;

	   //setTimeout("changeImg()",60*1000);//一分钟调用一次

	          }

changeImg();