SA:MP Plugin problem

#include <sampgdk\sdk\amx\amx.h>#include <sampgdk\sdk\plugincommon.h>#pragma comment(lib, "sampgdk3_s.lib")typedef void (*logprintf_t)(char* format, ...);logprintf_t logprintf;extern void *pAMXFunctions;cell AMX_NATIVE_CALL HelloWorld(AMX* amx, cell* params){    logprintf("This was printed from the Test plugin! Yay!");    return 1;}PLUGIN_EXPORT unsigned int PLUGIN_CALL Supports() {    return SUPPORTS_VERSION | SUPPORTS_AMX_NATIVES;}PLUGIN_EXPORT bool PLUGIN_CALL Load(void **ppData) {    pAMXFunctions = ppData[PLUGIN_DATA_AMX_EXPORTS];    logprintf = (logprintf_t) ppData[PLUGIN_DATA_LOGPRINTF];    logprintf(" * Test plugin was loaded.");    return true;}PLUGIN_EXPORT void PLUGIN_CALL Unload(){    logprintf(" * Test plugin was unloaded.");}AMX_NATIVE_INFO PluginNatives[] ={    {"HelloWorld", HelloWorld},    {0, 0}};PLUGIN_EXPORT int PLUGIN_CALL AmxLoad( AMX *amx ) {    return amx_Register(amx, PluginNatives, -1);}PLUGIN_EXPORT int PLUGIN_CALL AmxUnload( AMX *amx ) {    return AMX_ERR_NONE;}

1>------ Erstellen gestartet: Projekt: samppv4, Konfiguration: Debug Win32 ------
1>  helloworld.cpp
1>helloworld.obj : error LNK2001: Nicht aufgelöstes externes Symbol ""void * pAMXFunctions" (?pAMXFunctions@@3PAXA)".
1>c:\users\user\documents\visual studio 2010\Projects\samppv4\Debug\samppv4.dll : fatal error LNK1120: 1 nicht aufgelöste externe Verweise.
========== Erstellen: 0 erfolgreich, Fehler bei 1, 0 aktuell, 0 übersprungen ==========