getting method from Form1 , then execute in Form2 .. Why doesnt work ?

public void ShowInListWiev() // my method.when i call it in PhoneBook forms's button , it should get datas to the lisTWiev located in Mainform
{
OleDbConnection con = new OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=data.accdb;Persist Security Info=False;");
OleDbCommand veri = new OleDbCommand("SELECT id, ad, soyad,cep,mail,web,operator,adres FROM rehber ORDER BY id", con);
OleDbDataReader oku;
con.Open();//baglantıyı acar
oku = veri.ExecuteReader();//verileri cekme komutunu calıstırır

lstRehber.Items.Clear();//listview in içeriğini temizler
while (oku.Read())//database deki verileri listview e yazdırır
{
ListViewItem rehberItem = new ListViewItem(oku["id"].ToString());
rehberItem.SubItems.Add(oku["ad"].ToString());
rehberItem.SubItems.Add(oku["soyad"].ToString());
rehberItem.SubItems.Add(oku["cep"].ToString());
rehberItem.SubItems.Add(oku["mail"].ToString());
rehberItem.SubItems.Add(oku["web"].ToString());
lstRehber.Items.Add(rehberItem);
}
oku.Close();
con.Close();//baglantıyı kapatır






}