C语言piano

#include <windows.h>   
#include <stdio.h> 
#include <stdlib.h> 
#include <conio.h>
#pragma comment(lib,"winmm.lib")
typedef union _midi {
DWORD dwData;
BYTE bData[4];
} MIDI;
void setInstruments(HMIDIOUT handle, unsigned long *result, unsigned long *device);
void printtable(unsigned long device);
int main() 
{ 
unsigned long result, device=0;   
HMIDIOUT handle;   
unsigned char key; 
printf("initlizing ...\n");   
result=midiOutOpen(&handle,0,0,0,CALLBACK_NULL);   
if(result) 
{ 
   printf("There is an error opening the default MIDI out device!\n"); 
   exit(1);
}
setInstruments(handle, &result, &device);
// printf("current volume 0x%x\n",result);   
while(TRUE)   
{ 
   key=getch();
   midiOutReset(handle);
   switch(key)   

   { 
   case 'a': 
    midiOutShortMsg(handle, 0x00603C90);   
    // Sleep(1000);   
    break; 
   case 's': 
    midiOutShortMsg(handle, 0x00603E90);   
    // Sleep(1000); 
    break; 
   case 'd': 
    midiOutShortMsg(handle, 0x00604090);   
    // Sleep(1000);   
    break; 
   case 'f': 
    midiOutShortMsg(handle, 0x00604190);   
    // Sleep(1000); 
    break; 
   case 'j': 
    midiOutShortMsg(handle, 0x00604390);   
    // Sleep(1000); 
    break; 
   case 'k': 
    midiOutShortMsg(handle, 0x00604590);   
    // Sleep(1000); 
    break; 
   case 'l': 
    midiOutShortMsg(handle, 0x00604790);   
    // Sleep(1000); 
    break; 
   case 'z':