How can I use Wallet in C# to connect to the RDBMS without password?

@dbname)

 The wallet is working fine with SQL*Plus (sqlplus /@dbname). The wallet is working fine in VBScript too. But how can I use it in C#?

This is with password:
conn = new OracleConnection(String.Format("User Id={0};Password={1};Data Source={2}", uname, pwd, connectTo));
conn.Open();

I tried this for wallet:
conn = new OracleConnection(String.Format("Data Source={0}", connectTo));
conn.Open();

But it does not work.
Is it possible at all?

thanks,
gabor