JQuery :: Find Parent Tag Value Using Jquery

i designed a gridview and innergridview. design seems below

Master Data
Detail Data
Master Data

i have some hidden control in the master record, in child row when i click an link button then i want to read that hdden value so, i use below code var data1 = closestTR.find('input:hidden[id$=hdnData1]').val(); but its not working , the same code is working with the event from Master Record. may i know how to read that master row record from the child row using jquery.? for this master and child row concepts i used below syntax

<gridview>
<HeaderTemplate>
<table>
<tr><td>This is for Master Row Header</td></tr>
</table>
</HeaderTemplate>
<ItemTemplate>
<table>
<tr><td>This is for Master Row Data</td></tr>
</table>
</ItemTemplate>
<innerGridview>
<HeaderTemplate>
<table>
<tr><td>This is for Detail Row Heading</td></tr>
</table>
</HeaderTemplate>
<ItemTemplate>
<table>
<tr><td>This is for Master Row Data</td></tr>
</table>
</ItemTemplate>
</innerGridview>
<gridview>