ASP.NET

<asp:panel id="PanelOutDCItemDetails" runat="server">
<asp:gridview id="gvOutDCItemDetails" runat="server" allowpaging="True"
="" pagesize="6" autogeneratecolumns="False" onrowdatabound="gvOutDCItemDetails_RowDataBound" onrowcommand="gvOutDCItemDetails_RowCommand" onselectedindexchanged="gvOutDCItemDetails_SelectedIndexChanged" backcolor="White" bordercolor="White" borderstyle="Ridge" borderwidth="2px" cellpadding="3" cellspacing="1" gridlines="None" datakeynames="Item_Id">
<columns>
<asp:commandfield showdeletebutton="True">
<asp:boundfield headertext="Item Id" datafield="Item_Id">
<asp:boundfield headertext="Item Name" datafield="IName">
<asp:boundfield headertext="Net Quantity" datafield="I_Quantity">
<asp:boundfield datafield="Remaining_Qty" headertext="Remaining Quantity">
<asp:templatefield headertext="Process">
<itemtemplate>
<asp:dropdownlist id="ddrProcess" runat="server">




<asp:templatefield headertext="Dispatch Quantity">
<itemtemplate>
<asp:textbox id="txtDispatchQuantity" runat="server" autopostback="true" ontextchanged="TextChanged_txtDispatchQuantity">

<asp:templatefield headertext="Remaining Quantity">
<itemtemplate>
<asp:textbox id="txtRamainingQuantity" runat="server">

<asp:templatefield headertext="Rate">
<itemtemplate>
<asp:textbox id="txtRate" runat="server" autopostback="true" ontextchanged="txtRate_TextChanged">

<asp:templatefield headertext="Amount">
<itemtemplate>
<asp:textbox id="txtAmount" runat="server">

<asp:templatefield>
<itemtemplate>
<asp:label id="lblStatus" runat="server" text="Status">



<footerstyle backcolor="#C6C3C6" forecolor="Black">
<headerstyle backcolor="#4A3C8C" font-bold="True" forecolor="#E7E7FF">
<pagerstyle backcolor="#C6C3C6" forecolor="Black" horizontalalign="Right">
<rowstyle backcolor="#DEDFDE" forecolor="Black">
<selectedrowstyle backcolor="#9471DE" font-bold="True" forecolor="White">
<sortedascendingcellstyle backcolor="#F1F1F1">
<sortedascendingheaderstyle backcolor="#594B9C">
<sorteddescendingcellstyle backcolor="#CAC9C9">
<sorteddescendingheaderstyle backcolor="#33276A">

<selectedrowstyle backcolor="#9471DE" font-bold="True" forecolor="White">


Here is my C# code

protected void gvOutDC_SelectedIndexChanged1(object sender, EventArgs e)
   {
       if (gvOutDC.SelectedIndex >= 0)
       {
           btnsave.Enabled = false;
           btnInword.Visible = false;

           OutDC.Visible = true;
           OutDCItemDetails.Visible = true;
           View.Visible = false;
           InwordDetails.Visible = false;
           txtOutId.Visible = true;
           txtoutCode.Enabled = false;
           btn.Visible = true;
           txtcustcode.Enabled = false;
           btnsave.Enabled = true;


           txtOutId.Text = gvOutDC.SelectedDataKey[0].ToString();

           txtoutCode.Text = gvOutDC.SelectedRow.Cells[2].Text.ToString();
           txtDate.Text =gvOutDC.SelectedRow.Cells[8].Text.ToString();
           txtCustomerId.Text = gvOutDC.SelectedRow.Cells[5].Text.ToString();
           txtcustcode.Text = gvOutDC.SelectedRow.Cells[7].Text.ToString();
           txtCustomerName.Text = gvOutDC.SelectedRow.Cells[6].Text.ToString();
           int inworditem = Convert.ToInt16(gvOutDC.SelectedRow.Cells[3].Text.ToString());
           SqlCommand cmd = new SqlCommand("sp_getOutDCmaterialDetail",con1);
           cmd.CommandType = CommandType.StoredProcedure;
           cmd.Parameters.AddWithValue("@outDCid", txtOutId.Text);
           cmd.Parameters.AddWithValue("@inwordItem", inworditem);
           SqlDataAdapter da = new SqlDataAdapter(cmd);
           DataSet ds = new DataSet();
           da.Fill(ds);

          //.Text = ds.Tables[0].Rows[0][0].ToString();
           con1.Open();
           //SqlDataReader dr=cmd.ExecuteReader();
           //if (dr.HasRows)
           //{
           //    while (dr.Read())
           //    {

           //    }
           //}

           gvOutDCItemDetails.DataSource = ds;
           gvOutDCItemDetails.DataBind();

           OutDCItemDetails.Visible = true;


       }
   }

  protected void gvOutDCItemDetails_RowDataBound(object sender, GridViewRowEventArgs e)
   {
       if (e.Row.RowType == DataControlRowType.DataRow)
       {
           //if ((e.Row.RowState & DataControlRowState.Edit) > 0)
           //{
               DropDownList ddList = (DropDownList)e.Row.FindControl("ddrProcess");
               //bind dropdownlist

               SqlCommand cmd = new SqlCommand("sp_getProcess", con1);
               cmd.CommandType = CommandType.StoredProcedure;
               SqlDataAdapter da = new SqlDataAdapter(cmd);
               DataSet ds = new DataSet();
               da.Fill(ds);
               DataTable dt = ds.Tables[0];
               //DataTable dt = con1.GetData("Select category_name from category");
               ddList.DataSource = dt;
               ddList.DataTextField = "PName";
               ddList.DataValueField = "Process_Id";
               ddList.DataBind();
               ddList.Items.Insert(0,new ListItem("--SELECT--","0"));

               TextBox txtDispatchQuantity = (TextBox)e.Row.FindControl("txtDispatchQuantity");
               txtDispatchQuantity.Text = ds.Tables[0].Rows[0][3].ToString();

               TextBox txtRamainingQuantity = (TextBox)e.Row.FindControl("txtRamainingQuantity");
               txtRamainingQuantity.Text = ds.Tables[0].Rows[0][3].ToString();

               TextBox txtRate = (TextBox)e.Row.FindControl("txtRate");
               txtRate.Text = ds.Tables[0].Rows[0][3].ToString();


               TextBox txtAmount = (TextBox)e.Row.FindControl("txtAmount");
               txtAmount.Text = ds.Tables[0].Rows[0][3].ToString();


               }
       if (e.Row.RowType == DataControlRowType.Footer)
       {

         //  Label lblTotalPrice = (Label)e.Row.FindControl("Total_Amount");

           //lblTotalPrice.Text = total.ToString();
          // txttotalAmount.Text = Total.ToString();
       }

   }

for update record in my OutWordChallan Page
On selectedindexchaged i want to set vaues of textbox in item template of gridview ...
using dataset ...
but how can i assign vaues when we actually dont know how many rows in my dataset
please help me thr this
really thankfull