Hi I would like to make a call to the unmanaged code using PInvoke, yet I found that there is a little documentation in the internet which most of them are form microsoft web sites, I hope some one can tell me where to look for infor about using PInvoke. And I found some articles in http://samples.gotdotnet.com/quickstart/CompactFramework/. About using PInvoke in Ms.net CF. The reason why I try to find documentation about PInvoke is because most hard things in MS.net CF can only be done by accessing direct to native /unmanaged code, and thus I need to do so. Here in http://samples.gotdotnet.com/quickstart/CompactFramework/ there are some samples to do PInvoke, yet they don't explain how can they know what methods available in the unmanged / native code. For example, given this code DllImport("CoreDll.DLL", EntryPoint="PlaySound", SetLastError=true)] private extern static int WCE_PlaySound(string szSound, IntPtr hMod, int flags); I am confused and can't find a documentation about these 1. How do I know what dll to import ? 2. What available dll can I use ? 3. What methods can available in a particular dll ? 4. What does a methods do ? 5. What are the parameters of a particular methods ? (as vs.net intellisense is not helpfull in this case) Therefore I think there should be some documentation out there that explain about all these in details. I have downloaded the PocketPC SDK and yet I can't find any documentation in it describing about all these. Hope someone can help me to find out about the documentation. Thank's