Ok I soppose ur datagrid has the same value as ur textBox!
First u fill need 4 commands for Select/Update/Insert/Delete.
& As Microsoft recomended make 4 SPs in ur Datanbase (in MS-SQL)
Then fill ur dataset & [u]bind</u> ur controls & then when u updated ur controls cuz they r binded the Dataset will update so u will only need to call ur DataAdapter.Update() method!
& about inserts let me tell u by a simple sample.
DataRow anyRow = ExistingTable.NewRow();
anyRow = "Jay";
anyRow = "Stevens";
& Then call
HTH, & plz keep in touch in every faced problem.