reflecting changes made to the datagrid back on the dataset and the datatable
<p>i have a datagrid which has a dataset as its datasource and that dataset contains a table from a database.what i need is when i make changes to cell values in datagrid, the changes should also reflect back on the database. the thing is these changes do get reflected on the dataset but when i use da.Update(ds,"TableName") to forward that changes to database,it does not work. The database still shows the old value even though the datagrid and dataset shows the updated value. 
i have used the da.Update() command twice in the same program at other places and there it seems to work properly and the database shows the updated value. i dont know wats causing it to not work this time. wats suprising is that i am not even getting any errors, the code executes properly but no changes are seen in the database.
someone kindly help!!!</p>

<p><strong>edit:</strong> actually, what i am doing is i am selecting a row from a datagrid and then displaying all the cell values from that row on textboxes. then i am editing those values and saving them using foll. code</p>

<p>private void btnSave_Click(object sender, EventArgs e)
{
  dgDetails.SelectedCells[0].Value = txtPurpose.Text;
   da.Update(ds, "Scheduler");
}</p>

<p>no one has the solution for the problem????</p>
