var i=0;  
    var adl=new Array(4,4,4); 
    //6是设置的时间 
    var timer=setInterval("run()",adl[i]*1000); 
    function run() 
    { 
        for(j=0;j<adl.length;j++) 
        { 
            var x=document.getElementById("srh"+j); 
            if(j==i) x.style.display="block"; 
            else x.style.display="none"; 
        } 
        clearInterval(timer); 
        timer=setInterval("run()",adl[i]*1000); 
        i=(i<adl.length-1)?++i:0; 
    }