//Thanks!! CSS HappyLife & Lios K

(function(onLoad) {  
    try {  
        window.addEventListener('load', onLoad, false);  
    } catch (e) {  
        window.attachEvent('onload', onLoad);  
    }  
})(function() {  
  var tags = ["img","input"];  
  for( var i=0, len=tags.length; i<len; i++ ) {  
    var over = function() { this.src = this.src.replace('_off.', '_on.'); };  
    var out  = function() { this.src = this.src.replace('_on.', '_off.'); };  
    var el = document.getElementsByTagName(tags[i]);  
    for (var j=0, len2=el.length; j<len2; j++) {  
      var attr = el[j].getAttribute('src');  
      if (!el[j].src.match("_off.")&&attr) continue;  
      el[j].onmouseover = over;  
      el[j].onmouseout  = out;  
    }  
  }  
});