How to solve error Unable to cast object of type 'System.Web.UI. WebControls.Dat aContr

[sana krishna]

Hai,
Pls anyone help me............. ..............
I am using ASP.NET(C#).
I want to display the data in a gridview and make the gridview to become editable and insert and delete.
But i can't perform edit .
when i click update button
It display a error message like this......

Unable to cast object of type 'System.Web.UI. WebControls.Dat aControlLinkBut ton' to type 'System.Web.UI. WebControls.Tex tBox'.

My code is
protected void grdvwteleno_Row Editing(object sender, GridViewEditEve ntArgs e)
{
grdvwteleno.Edi tIndex = e.NewEditIndex;
BindData();
}
protected void grdvwteleno_Row Updating(object sender, GridViewUpdateE ventArgs e)
{
DataTable dt = (DataTable)Sess ion["dt"];

GridViewRow row = grdvwteleno.Row s[e.RowIndex];
dt.Rows[grdvwteleno.Edi tIndex]["SL"] = ((TextBox)(row. Cells[1].Controls[0])).Text.ToStrin g();
dt.Rows[grdvwteleno.Edi tIndex]["Name"] = ((TextBox)(row. Cells[2].Controls[0])).Text.ToStrin g();
dt.Rows[grdvwteleno.Edi tIndex]["Id"] = ((TextBox)(row. Cells[3].Controls[0])).Text.ToStrin g();

[Plater]

Sometimes I wonder about the language barrier.
That error message is very clear. One of those things you think is a TextBox, is really a DataControlLink Button. Figure out which one (it probably pointed to the offending line number in the error message) and correct your mistake.