I have a time table as below:

```

<table id="timetable">
<tr><td>00:00</td><td id="tm0"></td></tr>
<tr><td>00:30</td><td id="tm1"></td></tr>
<tr><td>01:00</td><td id="tm2"></td></tr>
<tr><td>01:30</td><td id="tm3"></td></tr>
</table>

```

so if i want insert <span></span> into <td> start from id="tm0" - id="tm3" how can i make it ?? instead of "rowspan" can anyone help ??