mongodb connection

public static MongoDatabase Connect(string connectionString)
{
  if (string.IsNullOrWhiteSpace(connectionString))
    throw new System.ArgumentNullException("invalid connection string");
 
  var mongoConnStr = MongoUrl.Create(connectionString);
 
  MongoClient client = new MongoClient(mongoConnStr);
	MongoServer server = client.GetServer();
	if (server.State == MongoServerState.Disconnected)			
		server.Connect();
 
  return server.GetDatabase(mongoConnStr.DatabaseName);
}