help: sendmessage function

[llee]

I'm trying to call the SendMessage function as defined in the windows api.
Unfortunately every attempt to call it results in an error.
Initially I tried calling the function directly assuming that it would have been
imported into my applications namespace after: 
" import std.c.windows.windows; "
this failed. So I tried:
" extern (Windows) void SendMessage (HWND, uint, WPARAM, LPARAM); "
this got the problem past the compiler, but generated an error during linkage.
At this stage I'm open for alternatives.
I'm trying to update a client window after my program processes WM_CHAR
messages. I was trying to use the SendMessage function to trigger WM_PAINT
events. 
Any help would be appreciated.
thanks, 
lee