Forms Data Controls :: Textbox Returns Null

I have a gridview. In the rowupdating event, the txtbox returns null. I have enabled viewstate for the gridview. But still it does not work. I have made this in Kentico.

<asp:GridView ID="GridView1" runat="server" AllowPaging="True" AllowSorting="True"
AutoGenerateColumns="False" DataKeyNames="id" DataSourceID="SqlDataSource1" EnableModelValidation="True"
OnRowUpdating="GridView1_RowUpdating" >
<Columns>
<asp:CommandField ShowDeleteButton="True" CausesValidation="false" ShowEditButton="True"
ControlStyle-Width="100px" />
<asp:TemplateField HeaderStyle-HorizontalAlign="Left" HeaderText="Name" SortExpression="name">
<ItemTemplate>
<asp:Label ID="lblRegionName" runat="Server" Text='<%# Bind("name") %>' Width="200px"></asp:Label>
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox runat="server" ID="EditRegionName" OnTextChanged="EditRegionName_Updated"
Text='<%# Bind("name") %>' Width="200px" />
</EditItemTemplate>
<FooterTemplate>
<asp:TextBox runat="server" ID="InsertRegionName" Text='' Width="200px" />
</FooterTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderStyle-HorizontalAlign="Left" HeaderText="Archived" SortExpression="IsArchive">
<ItemTemplate>
<asp:CheckBox ID="lblArchive" Enabled="false" runat="Server" Checked='<%# DataBinder.Eval(Container.DataItem, "archived") %>'
Width="100px" />
</ItemTemplate>
<EditItemTemplate>
<asp:CheckBox runat="server" OnCheckedChanged="EditArchive_CheckedChanged" ID="EditArchive"
Width="100px" />
</EditItemTemplate>
<FooterTemplate>
<asp:CheckBox runat="server" ID="InsertArchive" Checked="false" Width="100px" />
</FooterTemplate>
</asp:TemplateField>
<asp:TemplateField ShowHeader="False">
<ItemTemplate>
<asp:LinkButton ID="btnHistory" runat="server" Text="History"></asp:LinkButton>
<ajaxToolkit:ModalPopupExtender OkControlID="OkButton" ID="ModalPopupExtender1" runat="server"
BackgroundCssClass="modalBackground" TargetControlID="btnHistory" PopupControlID="Panel1" />
<asp:Panel ID="Panel1" runat="server" CssClass="modalPopup" Style="display: none">
<div>
<iframe frameborder="0" src="/CMSWebParts/MSM/RoundTableAfrica/Beheer/History.aspx?id=<%# DataBinder.Eval(Container.DataItem, "id") %>"
width="500px" height="100%" scrolling="no"></iframe>
<br />
<asp:Button ID="OkButton" runat="server" Text="OK" CausesValidation="false" Width="50" />
</asp:Panel>
</div>
</ItemTemplate>
<EditItemTemplate>
</EditItemTemplate>
<FooterTemplate>
<asp:Button ID="btnInsert" runat="server" Text="Insert" OnClick="Insert_Click" />
</FooterTemplate>
</asp:TemplateField>
</Columns>
<EmptyDataTemplate>
Region Name:<asp:TextBox runat="server" ID="NoDataRegionName" />
Archived:<asp:CheckBox runat="server" ID="NoDataIsArchive" />
<asp:Button runat="server" ID="NoDataInsert" CssClass="contentButton" Text="Insert"
OnClick="Button1_Click" />
</EmptyDataTemplate>
</asp:GridView>
<asp:Button runat="server" ID="Add" Text="Add" OnClick="Add_Click" />
<asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:RTAConnectionString%>"
ProviderName="System.Data.SqlClient" SelectCommand="select * from [spiderwebs_region] order by name "
UpdateCommand="UpdateRegionWithHistory" UpdateCommandType="StoredProcedure"
DeleteCommand="DeleteRegionWithHistory" DeleteCommandType="StoredProcedure" OnInserting="Sqldatasource1_Inserting"
OnInserted="Sqldatasource1_Inserted" InsertCommand="InsertRegionWithHistory"
InsertCommandType="StoredProcedure">
<DeleteParameters>
<asp:Parameter Name="id" Type="Int32" />
</DeleteParameters>
<InsertParameters>
<asp:Parameter Name="action_time" Type="DateTime" />
</InsertParameters>
<UpdateParameters>
<asp:Parameter Name="content_type_id" Type="Int32" />
<asp:Parameter Name="object_repr" Type="String" />
<asp:Parameter Name="action_flag" Type="Int32" />
</UpdateParameters>
</asp:SqlDataSource>
Code Behind:
protected void Page_Load(object sender, EventArgs e)
{
GridView1.DataBind();
}
protected void GridView1_RowUpdating(Object sender, GridViewUpdateEventArgs e)
{
int index = e.RowIndex;
GridViewRow currentrow = ((GridView)sender).Rows[index];
TextBox txtbox = (TextBox)currentrow.FindControl("EditRegionName");
CheckBox isarchive = (CheckBox)currentrow.FindControl("EditArchive");
e.NewValues["name"] = txtbox.Text;
e.NewValues["archived"] = isarchive.Checked;
GridView1.EditIndex = -1;
GridView1.DataBind();
}