function showTeachInfo(count,sid,aName,dName)
{
    var obj,lbl;
    for(i=1;i<=count;i++)
    {
        obj=document.getElementById(dName+i);
        lbl=document.getElementById(aName+i);
        if(i!=sid)
        {
            obj.style.display='none';
            lbl.parentElement.background='images/zyzx_9.gif';
        }
    }
    obj=document.getElementById(dName+sid);
    lbl=document.getElementById(aName+sid);
    obj.style.display='';
    lbl.parentElement.background='images/zyzx_12.gif';
}