>>>On the same page I have a GridView bound to a dataset. Below the GridView there is a textbox (or several textboxes). As user navigates through the GridView (clicking on this or that row) I want the value/text in the textbox(s) to be updated according to new row in the dataset. My understanding is I need to bind the textbox(s) to the same dataset. How do you do it? An example, of one textbox binding to the dataset would be very helpful.
>>
>>If you don't mind round-tripping to the server you can wire up the GridView.SelectedIndexChanged event and do something like this:

protected void GridView1_SelectedIndexChanged(object sender, EventArgs e)
>>        {
>>            TextBox1.Text = GridView1.SelectedRow.Cells[2].Text;
>>            //etc
>>        }

>
>I prefer not to make the "trip" back to the server. I am working on having a button field on the GridView and wire it to a method of the page. The only thing I don't know - yet - if the page has to be reposted on the call to this method. If so I will look for way to do it with jQuery so there is no reposting of the page and no trip back to the server.
>Thank you.

Not quite so easy. Wire up the GridView.RowDataBound event in c#:

       protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
        {
            if (e.Row.RowType == DataControlRowType.DataRow)
            {
                e.Row.Attributes.Add("onClick", "javascript:void selectRow(this);");
            }
        }

then script on the page:

 function selectRow(i) {
            document.getElementById("TextBox1").value = i.cells[5].innerText;
        }