The biggest problem in your code is that you use ODBC to connect to Oracle. You should use ODP.NET, which is even recommended by Microsoft. What you doing is there [most likely] for backwards compatibility and not to write the new stuff.
Here your problem is in connection string, which should look like this
"DSN=oracledsn;UID=myUID;PWD=myPWD;Integrated Security=no;"
And you don't need command
just to test connection
using cn= New OdbcConnection(".....")
cn.Open()
if cn.State = ConnState.Open Then MessageBox.Show(...)
end using
When you use using
it will take care of closing and disposing of connection.