private void savebuyers_Click(object sender, RoutedEventArgs e)
{
        string connectionstring = null;
        connectionstring = "Data Source=FRANCIS;Initial Catalog=Pam Golding;Integrated Security=SSPI";
        SqlConnection con = new SqlConnection(connectionstring);

        try
        {
            string query;
            query = "insert into buyers (name,number,email) values ('" + namebuyers.Text + "'," + Convert.ToInt32(numberbuyers) + ",'" + emailbuyers.Text + "')";
            SqlCommand command = new SqlCommand(query, con);
            message1.Text = "Data Saved Successfully!";
            con.Open();
            command.ExecuteNonQuery();
            con.Close();
        }
        catch
        {
            message1.Text = "Error While Saving Data!";
        }
}

Convert.ToInt32(numberbuyers.Text)