Data Controls :: Nested GridView With TextBoxes - Unwanted Comma In TextBox After PostBack

I used the code for gridview within a gridview using jquery functions for expanding and collapsing as shown in article : [URL] .... It works well, but I have textbox in childgrid and it behaves wrongly when i submit childgrid data for saving, it shows character comma (,) before data entered in textboxes.

I commented all coding for submit button outside both grids, then also on clicking of submit button, there comes comma automatically in textboxes in child grid..

--------------design------------------
<script type="text/javascript">
$("[src*=plus]").live("click", function () {
$(this).closest("tr").after("<tr><td></td><td colspan = '999'>" + $(this).next().html() + "</td></tr>")
$(this).attr("src", "images/minus.png");
});
$("[src*=minus]").live("click", function () {
$(this).attr("src", "images/plus.png");

[code].....