GridView, dataTable and two way binding

[witek]

I am lost.

There is a dataTable with data which I want to dispaly in GridView.
dataTable is not connected to any database. Just dataTable with data.

There is a class wich is used as column template
//-------------------------------------------------------------------------------------------------------
public class TextBoxTemplate :ITemplate
{
DataControlRowType m_rowType;
string m_dataField;

public TextBoxTemplate (DataControlRowType rowType, string dataField)
{
m_rowType = rowType;
m_dataField = dataField;
}

void ITemplate.InstantiateIn (System.Web.UI.Control container)
{
TextBox txt = new TextBox ();
txt.DataBinding += new EventHandler (txt_DataBinding);
container.Controls.Add (txt);
}

void txt_DataBinding (object sender, EventArgs e)
{
TextBox txt = (TextBox)sender;
GridViewRow row = (GridViewRow)txt.NamingContainer;
txt.Text = DataBinder.Eval
(row.DataItem, this.m_dataField).ToString ();
}
}
//-------------------------------------------------------------------------------------------------------
GridView is build dynamically.

//-------------------------------------------------------------------------------------------------------
for (int i = 0; i < dt.Columns.Count; i++)
{
TemplateField tf = new TemplateField ();
tf.ItemTemplate = new TextBoxTemplate
(DataControlRowType.DataRow, dt.Columns[i].ColumnName);
gv.Columns.Add (tf);
}
//-------------------------------------------------------------------------------------------------------

and finally bound.

//-------------------------------------------------------------------------------------------------------
gv.DataSource = dataTable;
gv.DataBind ();
//-------------------------------------------------------------------------------------------------------

and now here is a question.

How to acomplish two way bindig, to have data back in dataTable (for
example after clicking button on a page)?
I can't find any documentation how to do that.

I found something about IBindableTemplate and ExtractValues but I don't
know how to use that.
for some resons I can't use DataSourceID, I can't build DataSourceObject
class.
The only thing which I can is having gridview and datatable.
Thanks