Issues around using GetAsyncKeyState(int vKey ) function

Hi,
I'm developing a Windows Smart Client application with
C#.NET. I'm
trying to
implement Delayed Event Handling while loading the contents
of the grid
for
better user experience. When the grid fires the
RowSelectionChangedEvent, I would like to
I would like to check what caused the event, keyboard or the
mouse
click. The way to check for
mouse clicks is by using  GetAsyncKeyState(int vKey ) found
in the DLL
User32.dll.
It would be helpfull if anyone could share ideas around:
1) Any security aspect which needs to be considered by
importing the
User32.dll
in the .NET application.
2) Any performance issues related to com-interoperabality.
3) Any other advantages or disadvantages of using this dll
in the .Net
application. 

Any ideas and thoughts will be valuable.
Thanks
Ambuj