Help with getting element with jQuery

I posted a similar question and it got answered correctly but it wasn't really what I was after (my bad).

Let's say I have the HTML:

<TD nowrap="true" valign="top" width="190px" class="ms-formlabel">
<H3 class="ms-standardheader">
        <nobr>Islands</nobr>
    </H3></TD>
        <TD valign="top" class="ms-formbody">
            <span dir="none"><table>
            <tr><td><span class="ms-RadioText" title="Tasmania"><input id="ctl00_m_g_f1c8ac33_8a36_42be_8901_5201d5b9eede_ctl00_ctl04_ctl02_ctl00_ctl00_ctl04_ctl00_ctl00" type="radio" name="ctl00$m$g_f1c8ac33_8a36_42be_8901_5201d5b9eede$ctl00$ctl04$ctl02$ctl00$ctl00$ctl04$ctl00$RadioButtons" value="ctl00" /><label for="...">Tasmania</label></span></td>
            </tr><tr><td><span class="ms-RadioText" title="Greenland"><input id="ctl00_m_g_f1c8ac33_8a36_42be_8901_5201d5b9eede_ctl00_ctl04_ctl02_ctl00_ctl00_ctl04_ctl00_ctl01" type="radio" name="ctl00$m$g_f1c8ac33_8a36_42be_8901_5201d5b9eede$ctl00$ctl04$ctl02$ctl00$ctl00$ctl04$ctl00$RadioButtons" value="ctl01" /><label for="...">Greenland</label></span></td>
            </tr><tr><td><span class="ms-RadioText" title="Hawaii"><input id="ctl00_m_g_f1c8ac33_8a36_42be_8901_5201d5b9eede_ctl00_ctl04_ctl02_ctl00_ctl00_ctl04_ctl00_ctl02" type="radio" name="ctl00$m$g_f1c8ac33_8a36_42be_8901_5201d5b9eede$ctl00$ctl04$ctl02$ctl00$ctl00$ctl04$ctl00$RadioButtons" value="ctl02" /><label for="...">Hawaii</label></span></td>
            </tr>
            </table></span>
</TD>
<TD nowrap="true" valign="top" width="190px" class="ms-formlabel">
<H3 class="ms-standardheader">
        <nobr>Countries</nobr>
    </H3></TD>
        <TD valign="top" class="ms-formbody">
            <span dir="none"><table>
            <tr><td><span class="ms-RadioText" title="Australia"><input id="ctl00_m_g_f1c8ac33_8a36_42be_8901_5201d5b9eede_ctl00_ctl04_ctl02_ctl00_ctl00_ctl04_ctl00_ctl00" type="radio" name="ctl00$m$g_f1c8ac33_8a36_42be_8901_5201d5b9eede$ctl00$ctl04$ctl02$ctl00$ctl00$ctl04$ctl00$RadioButtons" value="ctl00" /><label for="...">Australia</label></span></td>
            </tr><tr><td><span class="ms-RadioText" title="Greece"><input id="ctl00_m_g_f1c8ac33_8a36_42be_8901_5201d5b9eede_ctl00_ctl04_ctl02_ctl00_ctl00_ctl04_ctl00_ctl01" type="radio" name="ctl00$m$g_f1c8ac33_8a36_42be_8901_5201d5b9eede$ctl00$ctl04$ctl02$ctl00$ctl00$ctl04$ctl00$RadioButtons" value="ctl01" /><label for="...">Greece</label></span></td>
            </tr><tr><td><span class="ms-RadioText" title="UK"><input id="ctl00_m_g_f1c8ac33_8a36_42be_8901_5201d5b9eede_ctl00_ctl04_ctl02_ctl00_ctl00_ctl04_ctl00_ctl02" type="radio" name="ctl00$m$g_f1c8ac33_8a36_42be_8901_5201d5b9eede$ctl00$ctl04$ctl02$ctl00$ctl00$ctl04$ctl00$RadioButtons" value="ctl02" /><label for="...">UK</label></span></td>
            </tr>
            </table></span>
</TD>

Depending on which Island is selected I want to hide/show some other fields:

$("input[name=ctl00$m$g_f1c8ac33_8a36_42be_8901_5201d5b9eede$ctl00$ctl04$ctl02$ctl00$ctl00$ctl04$ctl00$RadioButtons]:radio").change开发者_运维问答(function() {
        var title = $(this).next().text();
        if(title == "Tasmania")
        {
            $('nobr:contains("Extra column")').closest('tr').hide();
        }
        else
        {
            $('nobr:contains("Extra column")').closest('tr').show();
        }
    });

which works and with the other radio button group I want to hide/show elements based on what country is selected. I prefer to not use these long id's and the closest unique identifier for the group is what's between the tags, i.e.

<nobr>Islands</nobr>
<nobr>Countries</nobr>

I started with trying to get the name for the radio button groups into variables but had no luck

var rb1 = $('nobr:contains("Extra column")').parent().parent().next().children().children().children().attr('id');
alert(rb1);

but I don't get the popup (code after executes successfully), how would you get the radio button group name by starting at Islands?

Thanks in advance.

If you want to shorten your selector, you can use the endswith selector...

$("input[name$=RadioButtons]:radio")

$("nobr").closest("td").next().find("input:radio") should do it