function resizeIframe(){
    if(top.location != self.location){
        var frames = window.parent.document.getElementsByTagName('iframe');
        for (var i=0;i<frames.length;i++){
            if (frames[i].name == self.name){
                frames[i].height = document.body.scrollHeight;
                frames[i].width = document.body.scrollWidth;
                break;
            }
        }
    }
}
resizeIFrameHeight();

------解决方案--------------------
ContentPlaceHolder 设定高度为100%

------解决方案--------------------
<table width="100%" height=100% border="0" align="center" cellpadding="0" cellspacing="0" >
 <tr>
   <td bgcolor="#daedfe" >
       <asp:ContentPlaceHolder ID="Counts"  runat="server">
       </asp:ContentPlaceHolder>
   </td>
 </tr>
</table>

------解决方案--------------------

所以有时候还是
DIV布局来的省事
用DIV好了啊

------解决方案--------------------
表格有时候就是光出洋相,如上面的方法还是没解决,就用DIV做吧