private void logout_btn_Click(object sender, EventArgs e)
{
ConnectToMySQL dbc = new ConnectToMySQL(user_id_lbl.Text, user_hash_lbl.Text);
string query = "DELETE FROM user_sessions WHERE user_id = '" + user_id_lbl.Text.ToString() + "' ;";
dbc.Delete(query);
loginEnable();
}