Here are a few good references:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cp
coninteropmarshaling.asp
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cp
conInteroperatingWithUnmanagedCode.asp
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cp
conmarshalingdatawithplatforminvoke.asp

Signature
HTH,
Kevin Spencer
Microsoft MVP
Chicken Salad Surgery
What You Seek Is What You Get.
> Hi,
> is any possibility how to use an old DLL library (created in Visual C++6)
> also in .NET 2005, in C# or in C++ application? How ? Tutotials needed .-)