Combobox value to database sql

Hello,

I am trying to pass combobox value to a database, using a 3 tier business logic. Currently my form page looks like this:

private void Savebtn_Click(object sender, EventArgs e)
        {
            try
            {
                SaveRole(tbroledesc.Text, /*combobox selected item gets passed here*/);
                MessageBox.Show("Club role saved successfully");
            }
            catch (Exception er)
            {
                MessageBox.Show(er.Message.ToString());
            }
        }

        public void SaveRole(string RoleDesc, /*combobox selecteditem*/)
        {
            ClubRoles cr = new ClubRoles();
            RoleCreatedBy = Convert.ToInt32(lstcreatedby.SelectedItem);

            cr.insertingclubroles(RoleDesc, RoleCreatedBy);

            gettingclubroles();     //refresh the list
        }

How can I pass what ever is selected in the combobox drop down as the parameter?

I am filling the combobox like this:

private void loadclient()
        {
            DataSet dsloadclient;
            dsloadclient = new ClubRoles().createdby();

            //need fix duplicate values
            DataTable dt = dsloadclient.Tables[0].DefaultView.ToTable(true, "ClientName", "ClientId");
            lstcreatedby.DataSource = dt;
            lstcreatedby.DisplayMember = "ClientName";
            lstcreatedby.ValueMember = "ClientId";
        }

Any help will be appreciated.

Thanks.