function mout(e) {
  var obj = (e.target) ? e.target : window.event.srcElement;
  var o = obj.src;
  obj.src = o.replace(/^(.*)_v(\..+)$/, function(all, m1, m2) { return m1 + m2; });
}
function mover(e) {
  var obj = (e.target) ? e.target : window.event.srcElement;
  var o = obj.src;
  obj.src = o.replace(/^(.*)(\..+)$/, function(all, m1, m2) { return m1 + '_v' + m2; });
}
function initiomo() {
  if (document.getElementsByTagName) {
    var elms = document.getElementsByTagName('img');
    for (var i = 0; i < elms.length; ++i) {
      var obj = elms[i];
      if (obj.className == 'iomo') {
        var org = obj.src;
        addEvent(obj, 'mouseout', function(e) { mout(e); });
        var rep = org.replace(/^(.*)(\..+)$/, function(all, m1, m2) { return m1 + '_v' + m2; });
        var img = new Image();
        img.src = rep;
        addEvent(obj, 'mouseover', function(e) { mover(e); });
      }
    }
  }
}
addEvent(window, 'load', initiomo);