//-----------------------------------------------------------------------------
  var idx = 0;

  var kAgogo = idx++;
  var kBelltree = idx++;
  var kBongo = idx++;
  var kCastanet = idx++;
  var kClaves = idx++;
  var kConga = idx++;
  var kCowbell = idx++;
  var kCuica = idx++;
  var kGuiro = idx++;
  var kMaracas = idx++;
  var kMatraca = idx++;
  var kScratch = idx++;
  var kShaker = idx++;
  var kTambourine = idx++;
  var kTimbales = idx++;
  var kTriangle = idx++;
  var kVibraslap = idx++;
  var kWoodBlock = idx++;
  var kMatracaV = idx++;

/*
  var kAgogo = idx++;
  var kWoodBlock = idx++;
  var kCowbell = idx++;
  var kCastanet = idx++;
  var kGuiro = idx++;
  var kCuica = idx++;
  var kClaves = idx++;
  var kConga = idx++;
  var kShaker = idx++;
  var kScratch = idx++;
  var kTambourine = idx++;
  var kTimbales = idx++;
  var kTriangle = idx++;
  var kVibraslap = idx++;
  var kBelltree = idx++;
  var kBongo = idx++;
  var kMatraca = idx++;
  var kMaracas = idx++;
  var kMatracaV = idx++;
*/

  var instname = new Array(20);
  instname[kAgogo] = "agogo";
  instname[kBelltree] = "belltree";
  instname[kBongo] = "bongo";
  instname[kCastanet] = "castanet";
  instname[kClaves] = "claves";

  instname[kConga] = "conga";
  instname[kCowbell] = "cowbell";
  instname[kCuica] = "cuica";
  instname[kGuiro] = "guiro";
  instname[kMaracas] = "maracas";

  instname[kMatraca] = "matraca";
  instname[kScratch] = "scratch";
  instname[kShaker] = "shaker";
  instname[kTambourine] = "tambourine";
  instname[kTimbales] = "timbales";

  instname[kTriangle] = "triangle";
  instname[kVibraslap] = "vibraslap";
  instname[kWoodBlock] = "woodblock";
  instname[kMatracaV] = "matracav";

  var kFirstSlide = kAgogo;
  var kLastSlide = kWoodBlock;

//-----------------------------------------------------------------------------
  function init(){
  	slideTimer = setTimeout("slideShow()", kTimerInterval);
  }

//-----------------------------------------------------------------------------
  var slideIdx = kConga;
  var kTimerInterval = 5000;
  var kTimerInterval2 = 10000;	// userが選択した後の間隔
  var slideTimer;

//-----------------------------------------------------------------------------
  function slideShow(){
    if (slideIdx == kLastSlide) {
      slideIdx = kFirstSlide;
    } else {
      slideIdx++;
    }
  	var img = "img/";
  	img += instname[slideIdx];
  	img += ".png";
  	document.main.src = img;
  	slideTimer = setTimeout("slideShow()", kTimerInterval);
  }

//-----------------------------------------------------------------------------
  function changeMainImg(pic){
    slideIdx = pic;
  	var img = "img/";
  	img += instname[slideIdx];
  	img += ".png";
  	document.main.src = img;
  	clearTimeout(slideTimer);
  	slideTimer = setTimeout("slideShow()", kTimerInterval2);
  }

//-----------------------------------------------------------------------------
  function changeInstHitImg(pic){
  	var img = "img/";
  	img += instname[pic];
  	img += ".png";
  	document.instHit.src = img;
  }

//-----------------------------------------------------------------------------
  function changeInstRubImg(pic){
  	var img = "img/";
  	img += instname[pic];
  	img += ".png";
  	document.instRub.src = img;
  }

//-----------------------------------------------------------------------------
  function changeInstShakeImg(pic){
  	var img = "img/";
  	img += instname[pic];
  	img += ".png";
  	document.instShake.src = img;
  }

//-----------------------------------------------------------------------------
  function changeInstVariousImg(pic){
  	var img = "img/";
  	img += instname[pic];
  	img += ".png";
  	document.instVarious.src = img;
  }