ODP.NET

hi all,

i using C++.net to build an application to access my oracle database. i'm using oracle express edition 10g. i can connect to the database which is in my pc, when the code is running on my pc.
but when i take my application to another pc in the same network my application crashes when connecting to the database.
it says
"
An unhandled exception of type 'System.NullReferenceException' occurred in Oracle.DataAccess.dll

Additional information: Object reference not set to an instance of an object.
"

i have also put the oracle.dataaccess.dll in my .exe folder.

my application crashes at the first line;

OracleConnection^ con1 = gcnew OracleConnection();
con1->ConnectionString = "User Id=Air;Password=*****;Data Source=10.8.148.211:1521/XE;";

but when i install oracle express edition 10g on that machine i am able to connect to the remote database.