菜单链接有关问题

<tr>    <td class="mouse menu_second_img" id="td2" onclick="show(2)" style="font-size: 14px">        合同管理    </td></tr><tr>    <td id="show2" style="display: none;">        <table width="100%" border="0" cellspacing="0" cellpadding="0">            <tr>                <td class="left">                    <table width="100%" height="24" border="0" cellpadding="0" cellspacing="0">                        <tr>                            <td width="40" align="center">                                <img src="../../images/5.png" width="16" height="16">                            </td>                            <td>                                添加合同[color=#FF0000](如何才能点击添加合同之后就链接到另外的'合同页面'呢?)[/color]                            </td>                        </tr>                    </table>                </td>            </tr>        </table>    </td></tr>cont页,由IFleft和IFright页组成<tr>    <td width="180" id="frmTitle" align="center" valign="top">        <iframe name="left" height="680" width="180" src="IFleft" frameborder="0" scrolling="no">            浏览器不支持嵌入式框架，或被配置为不显示嵌入式框架。</iframe>    </td>    <td width="8" valign="middle" onclick="switchSysBar()">        <img src="../../images/cont_19.gif" width="8" alt="" height="64" name="img1" id="img1"            title="打开/关闭左侧栏" style="cursor: hand;" />    </td>    <td align="center" valign="top" style="padding-right: 8px;">        <table style="width: 100%; height: 100%; table-layout: fixed;" border="0" cellpadding="0"            cellspacing="0">            <tr>                <td height="13" style="line-height: 13px;">                    <table width="100%" border="0" cellspacing="0" cellpadding="0" style="table-layout: fixed;">                        <tr>                            <td class="cont_tab_l">                                &nbsp;                            </td>                            <td class="cont_tab_m">                                &nbsp;                            </td>                            <td class="cont_tab_r">                                &nbsp;                            </td>                        </tr>                    </table>                </td>            </tr>            <tr>                <td>                    <table width="100%" height="100%" border="0" cellpadding="0" cellspacing="0" style="table-layout: fixed;">                        <tr>                            <td>                                <iframe name="I1" height="680" width="100%" src="IFright" border="0" frameborder="0"                                    scrolling="auto">浏览器不支持嵌入式框架，或被配置为不显示嵌入式框架。</iframe>                            </td>                        </tr>                    </table>                </td>            </tr>            <tr>                <td height="13" style="line-height: 13px;">                    <table width="100%" border="0" cellspacing="0" cellpadding="0" style="table-layout: fixed;">                        <tr>                            <td class="cont_tab_bl">                                &nbsp;                            </td>                            <td class="cont_tab_bm">                                &nbsp;                            </td>                            <td class="cont_tab_br">                                &nbsp;                            </td>                        </tr>                    </table>                </td>            </tr>        </table>    </td></tr>这里是main页面<frameset rows="90,*,20" cols="*" framespacing="0" frameborder="no" border="0">  <frame src="IFtop.aspx"  name="topFrame" scrolling="No" noresize="noresize" id="topFrame" frameborder="0" />  <frame src="IFcont.aspx" name="mainFrame" id="mainFrame" frameborder="0" />  <frame src="IFfoot.aspx" name="footFrame" id="footFrame" frameborder="0" /></frameset>