function swapimg(obj) {
  if(obj.src.match(/_f2.(jpg|gif|png)/)) {
    obj.src = obj.src.replace('_f2', '');
  } else {
    obj.src = obj.src.replace(/\.(jpg|gif|png)$/, "_f2.$1");
  }
}

$(document).ready(function(){
  $("#main img").css("display","none");
  $("#Main01").css("display","block");
  $("#thumb a").click(function(){
var Isrc = $(this).attr("href");
$("#main img").css("display","none");
$(Isrc).fadeIn();
  });
});