Forms Data Controls :: Adding Row In GridView Programmatically?

I have to add row in gridview dynamically when a button is clicked on my page

Each Row which have to be added contains a dropdownlist(ddlQues) in which questions are binded

On selecting question from ddlQuestion I have to bind another dropdownlist(ddlAnswers)with respective

answers in that row of gridview

So autopostback property of ddlQuestion is set to be true

Everytime when button is clicked a new row is inserted in gridview and same process repeats............


I had tried following javascript:

<script type="text/javascript">
function AddNewRecord()
{
var grd = document.getElementById('<%= gvResponse.ClientID %>');
alert(grd);
var tbod=grd.rows[0].parentNode;
var newRow=grd.rows[grd.rows.length - 1].cloneNode(true);
tbod.appendChild(newRow);
return false;
}
</script>

and calling this function on button

<asp:Button ID="btnResponse" runat="server" Text=" New Response" CssClass="button3" OnClientClick="return AddNewRecord();" />

Also I tried to solve it by C#

By both ways(either by javascript or by C#)New Row is added in gridview

But when I select question from ddlquestion then page is loaded and and the inserted row in gridview disappears

I am using asp.net 2.0 with C#