editing a gridview row with in the page

<asp:TemplateField HeaderText="Quantity" HeaderStyle-Width="40px" >
                    <ItemTemplate>
                    <asp:Label ID="lblq" runat="server" Text='<%# bind("Quantity") %>' ></asp:Label></ItemTemplate>
                    <HeaderStyle Width="40px"></HeaderStyle>
                    <EditItemTemplate><asp:TextBox ID="txteq" runat="server" Text='<%# bind("Quantity") %>'></asp:TextBox></EditItemTemplate>
                    <FooterTemplate ><asp:TextBox ID="txtq" runat="server" ForeColor="Blue" Width="40px"></asp:TextBox></FooterTemplate>
                    </asp:TemplateField>

protected void gv_RowEditing(object sender, GridViewEditEventArgs e)
        {
            gv.EditIndex = e.NewEditIndex;
            getdata();
        }

string QUAT = ((TextBox)gv.Rows[e.RowIndex].FindControl("txteq")).Text;
                int quat = Convert.ToInt32(QUAT.Trim());