// Submit Button adds a new guestbook entry to the database,
// clears the form and displays the updated list of guestbook entries
protected void submitButton_Click(object sender, EventArgs e)
{
// use GuestbookEntities DbContext to add a new message
using (GuestbookEntities dbcontext = new GuestbookEntities())
{
// create a new Message to add to the database; Message is
// the entity data model class representing a table row
Message message = new Message();
// set new Message's properties
message.Date = DateTime.Now.ToShortDateString();
message.Name = nameTextBox.Text;
message.Email = emailTextBox.Text;
message.Message1 = messageTextBox.Text;
// add new Message to GuestbookEntities DbContext
dbcontext.Messages.Add(message);
dbcontext.SaveChanges(); // save changes to the database
} // end using statement
// clear the TextBoxes
nameTextBox.Text = String.Empty;
emailTextBox.Text = String.Empty;
messageTextBox.Text = String.Empty;
// update the GridView with the new database table contents
messagesGridView.DataBind();
} // submitButton_Click
