在Iframe窗口打开模态窗口

<table width="100%" border="0" cellspacing="0" cellpadding="0">
          <tr valign="top">
              <td width="50%">
                <div class="e12con02one">
                  <iframe id="iframe1" width="100%" height="170px" border="1"  src=" http://dashboard2.xueda.com/erptop/Performance/1" frameborder="0" allowtransparency="true" marginwidth="0px" marginheight="0px" scrolling="no">
         </iframe>
                </div>
                <div class="e12con02one">
                         <iframe id="iframe2" width="100%" height="295px" border=""  src="http://dashboard2.xueda.com/erptop/RealTimeBattlefield/1" frameborder="0" allowtransparency="true" marginwidth="0px" marginheight="0px" scrolling="no">
         </iframe>
                </div>
            
          </td>
              <td width="50%" style="padding-left:10px;">
                <div class="e12con02one">
                             <iframe id="iframe4" width="100%" height="490px" border="1"  src="http://dashboard2.xueda.com/erptop/top/1" frameborder="0" allowtransparency="true" marginwidth="0px" marginheight="0px" scrolling="no">
                     </iframe>                
                </div>
                    
            </td>
            </tr>
            <tr>             
 <td colspan="2">
            <div class="clear"></div>
            <div class="e12dbrwbox">
                <iframe id="iframe6" width="100%" height="265px" border="1"  src="http://customer.xueda.com/ScheduleTask/WorkingList" frameborder="0" allowtransparency="true" marginwidth="0px" marginheight="0px" scrolling="no">
                     </iframe>
            </div>
         
             </td>
          </tr>
        </table>
上面是一个Home页中的一部分，现在我在WorkingList中有个新建链接，打开一个模态窗口，如何设置将整个Home页全部覆盖?(现在是指覆盖WorkingList这一部分)