Access db connection to C# desktop app

i have tried
OleDbConnection conn = new OleDbConnection(@"Provider=Microsoft.JET.OLEDB.4.0;" + @"data source=Db.mdb");
conn.Open();
OleDbDataAdapter adapter = new OleDbDataAdapter();
OleDbCommand command = new OleDbCommand("SELECT * from temp", conn);


but it gives an error on conn, as if the object has not been created...plzzz can anyone help me..thanx in advance