passing a different sql string to DataAdapter each time i click a button

Question

private void button1_Click(object sender, System.EventArgs e) { ds.Tables.Clear(); da.SelectCommand=new SqlCommand(textBox1.Text,sqlConnection1); da.Fill(ds,"myTable"); dataGrid1.SetDataBinding(ds,"myTable"); } I have a form with a textBox1, a dataGrid1 and a button1. In the textBox1 I write some sql code and I want to see the output in the grid. ds is a dataset and da is a dataAdapter that were instantiated once in the constructor without any parameters. (ds=new DataSet(), da=New DataAdapter()). My problems is that this code seems to execute only the first time I click the button. After the first time the datagrid doesn't change although i put different sql code in the textBox. Can somebody tell me why is this happening?