How to use SendInput

SendInput is declared in winuser.h but somehow I can't use it anyway; I get the error: 'SendInput' : undeclared identifier


Well, I extracted the declarations used for SendInput and put it in a seperate header file which ended up like this:

typedef struct tagMOUSEINPUT {
    LONG    dx;
    LONG    dy;
    DWORD   mouseData;
    DWORD   dwFlags;
    DWORD   time;
    DWORD   dwExtraInfo;
} MOUSEINPUT, *PMOUSEINPUT, FAR* LPMOUSEINPUT;

typedef struct tagKEYBDINPUT {
    WORD    wVk;
    WORD    wScan;
    DWORD   dwFlags;
    DWORD   time;
    DWORD   dwExtraInfo;
} KEYBDINPUT, *PKEYBDINPUT, FAR* LPKEYBDINPUT;

typedef struct tagHARDWAREINPUT {
    DWORD   uMsg;
    WORD    wParamL;
    WORD    wParamH;
} HARDWAREINPUT, *PHARDWAREINPUT, FAR* LPHARDWAREINPUT;

#define INPUT_MOUSE     0
#define INPUT_KEYBOARD  1
#define INPUT_HARDWARE  2

typedef struct tagINPUT {
    DWORD   type;

    union
    {
        MOUSEINPUT      mi;
        KEYBDINPUT      ki;
        HARDWAREINPUT   hi;
    };
} INPUT, *PINPUT, FAR* LPINPUT;

WINUSERAPI
UINT
WINAPI
SensdasdInput(
    UINT    cInputs,     // number of input in the array
    LPINPUT pInputs,     // array of inputs
    int     cbSize);     // sizeof(INPUT)


With this done I could use it and I tested it with the following code.

INPUT inputevents[2];
KEYBDINPUT keyevent;

keyevent.wVk = VK_UP;
keyevent.dwFlags = 0;
inputevents[0].type = INPUT_KEYBOARD;
inputevents[0].ki = keyevent;

keyevent.wVk = VK_UP;
keyevent.dwFlags = KEYEVENTF_KEYUP;
inputevents[1].type = INPUT_KEYBOARD;
inputevents[1].ki = keyevent;

SendInput(2, &inputevents[0], sizeof(inputevents[0]));


Now I got the follwing errer:

error LNK2001: unresolved external symbol "__declspec(dllimport) unsigned int __stdcall SendInput(unsigned int,struct tagINPUT *,int)" (__imp_?SendInput@@YGIIPAUtagINPUT@@H@Z)


So, Im just wondering how I should do to use SendInput? By the way, I got it to work in Visual Basic on the same computer.