i = 0;
 function Gundong() {
    var conID = "myTab1_Content" + i;
    var nTabsID = "nTabs" + i;
    Content = document.getElementById(conID).style.display = "block";
    Content = document.getElementById(nTabsID).className = "active"; 
    if (i != 0) {
         Content = document.getElementById("myTab1_Content0").style.display = "none";
         Content = document.getElementById("nTabs0").className = "normal"; 
    }
    if (i != 1) {
         Content = document.getElementById("myTab1_Content1").style.display = "none";
         Content = document.getElementById("nTabs1").className = "normal"; 
    }
    if (i != 2) {
         Content = document.getElementById("myTab1_Content2").style.display = "none";
         Content = document.getElementById("nTabs2").className = "normal"; 
     }
    i++;
    if (i > 2)
         i = 0;
    window.setTimeout("Gundong()", 3000);
 }