iehover = function()
{
   var a = document.getElementById('button');
   a.onmouseover = function() {this.className+=" iehover";}
   a.onmouseout  = function() {this.className=this.className.replace(new RegExp(" iehover\\b"), "");}
}
if (window.attachEvent) window.attachEvent("onload", iehover);