Javascript/画像クリックchange

var s1Img = new Array(
	"../img/m4.jpg",
	"../img/m5.jpg",
	"../img/reims.jpg"
);
s1Name.style.cursor = "pointer";
function s1Func(){
  var s1Random = Math.floor(Math.random() * s1Img.length );
  s1Name.src = s1Img[s1Random];
}

var s2Img = new Array();
s2Img[0] = new Image();
s2Img[0].src = "../img/m4.jpg";
s2Img[1] = new Image();
s2Img[1].src = "../img/m5.jpg";
s2Img[2] = new Image();
s2Img[2].src=  "../img/jura.jpg";
//画像番号用のグローバル変数
var s2Id = document.getElementById("s2Id");
s2Id.style.cursor = "pointer";
var i=0;
//画像切り替え関数
function s2Func(){
  //画像番号を進める
  if (i == s2Img.length-1){
  	i=0; 
  } else{ 
  	i++; 
  }
  //画像を切り替える
  s2Id.src = s2Img[i].src;
}