function bians(id)
{
for (var l=0;l<3;l++)
{
var e=document.getElementById("d"+l);
var f=document.getElementById("ss"+l);
if (l==id)
{
e.style.display="";
f.className=backgroupnd_middle1;
}
else
{
e.style.display="none";
f.className=backgroupnd_middle_current1;
}
}
}
