/*图片滚动*/
function s_swithimg(type,imgnum)
{
   document.getElementById("s_en_big").src=type; 
   
   document.getElementById("imgpage1").className="imgpage_no";
   document.getElementById("imgpage2").className="imgpage_no";
   document.getElementById("imgpage3").className="imgpage_no"; 
   switch(imgnum)
   {
      case "1":document.getElementById("imgpage1").className="imgpage_yes"; break;
      case "2":document.getElementById("imgpage2").className="imgpage_yes"; break;
      case "3":document.getElementById("imgpage3").className="imgpage_yes"; break;
   }
}