My details view is not updating?

could you please tell me why nothing happens when I update my details view using the following code
protected void newOrderDetailsView_ItemUpdating(object sender, DetailsViewUpdateEventArgs e) { TextBox txtNote = (TextBox)newOrderDetailsView.FindControl("txtNote"); TextBox txtOrderDate = (TextBox)newOrderDetailsView.FindControl("txtOrderDate"); TextBox txtDueDate = (TextBox)newOrderDetailsView.FindControl("txtDueDate"); TextBox txtCustPO = (TextBox)newOrderDetailsView.FindControl("txtCustPO"); TextBox txtContact = (TextBox)newOrderDetailsView.FindControl("txtContact"); string Query = "Update Orders Set note='" + txtNote.Text + "' ,orderDate =CAST('" + txtDueDate + "'AS DATETIME) ,dueDate = CAST('" + txtDueDate + "'AS DATETIME) ,customerPurchaseOrder='" + txtCus ...