function  toppage()
{
     //if  (self.location!=top.location)
     //{//for ie and firefox
         //parent.document.all("mainFrame").height=document.body.scrollHeight + 30;
        // 在iframe的onload的事件中加入代码。
        var frm = document.getElementById("mainFrame");
        var subWeb = document.frames ? document.frames["mainFrame"].document : frm.contentDocument;
        if(frm != null && subWeb != null)
        {
          frm.height = subWeb.body.scrollHeight;
        }
     //}
}


function sizeIframe(frameName)
{
        var frm = document.getElementById(frameName);
        var subWeb = document.frames ? document.frames[frameName].document : frm.contentDocument;
        if(frm != null && subWeb != null)
        {
          frm.height = subWeb.body.scrollHeight;
        }
}