Hi, I am struggling to convert some functions from a C++ DLL to some function references in VB.net I dont program in C++, so I am hoping someone can help me with converting a couple of function prototypes: This are the C++ prototypes: CP2101_Open(DWORD dwDevice, HANDLE* cyHandle); CP2101_GetProductString(DWORD dwDeviceNum, LPVOID lpvDeviceString, DWORD dwFlags); CP2101_Close(HANDLE cyHandle ); This is what i have in vb.net: Public Declare Function CP2101_Open Lib "CP2101.dll" (ByVal DeviceNum As Long, ByRef Handle As Long) As Integer Public Declare Function CP2101_GetProductString Lib "CP2101.dll" (ByVal DeviceNum As Long, ByRef DeviceString As String, ByVal Options As Long) As Integer Public Declare Function CP2101_Close Lib "CP2101.dll" (ByVal DeviceNum As Long) As Integer I am not sure that I am converting the pointer data types correctly etc from C++ to Vb.net. If some could check my work. Thanks Barry