function welcomeshowxia(divid,i)
{
    var n1=document.getElementById("nn3");
    var n2=document.getElementById("nn4");
    var n3=document.getElementById("nn5");
   
    n1.style.display="none";
    n2.style.display="none";
    n3.style.display="none";
  
    var divid=document.getElementById(divid);
    divid.style.display = "block";
    
    var img_d1=document.getElementById("img_3");
    var img_d2=document.getElementById("img_4");
    var img_d3=document.getElementById("img_5");
     
    img_d1.src = "images/main3_top3.jpg";
    img_d2.src = "images/main3_top4.jpg";
    img_d3.src = "images/main3_top5.jpg";
    var img = document.getElementById("img_"+i);
    
    img.src = 'images/main3_top'+i+'_over.jpg';
    
    
}