[jQuery] identify tables with same ID ( duplicate ids)

[jQuery] identify tables with same ID ( duplicate ids)


hi,
I have 2 questions here for the group..
1. Does Jquery have native functions or lib or plugins to support
conversion of HTML Table data into XML string ( which can then be
sent via AJAX to server for getting a respone) ?
2. If my html page has tables with same ID , how can i obtain a
handle to all these tables. Eg. there is html page with 3 tables of
which 2 tables have same id.
Can i get a handle to these tables using any method like
alert($('#Instructions').length);
This however give me length as 1 instead of 2 .
I tried using (IE only solution)
document.all('Instructions').length which works fine , but this does
not work if there is only 1 id . eg.
alert(document.all('UserData').length);
Any help is appreciated !!
sample code
-----------------------------
<table id='Instructions' border="1" cellpadding="0" cellspacing="1" >
<tbody>
    <tr>
        <td style="text-align: left; width:25%; vertical-align: top">
        Table 1
        </td>
        <td style="text-align: left; vertical-align: top">
            <input name="enter" />
        </td>
    </tr>
</tbody>
</table>
<table id='Instructions' border="1" cellpadding="0" cellspacing="1" >
<tbody>
    <tr>
        <td style="text-align: left; width:25%; vertical-align: top">
        Table 2
        </td>
        <td style="text-align: left; vertical-align: top">
            <input name="enter" />
        </td>
    </tr>
</tbody>
</table>
<table id='UserData' border="1" cellpadding="0" cellspacing="1" >
<tbody>
    <tr>
        <td style="text-align: left; width:25%; vertical-align: top">
        Table 3
        </td>
        <td style="text-align: left; vertical-align: top">
            <input name="enter" />
        </td>
    </tr>
</tbody>
</table>
TIA for reading this