function vIE(){return (navigator.appName=='Microsoft Internet Explorer')?parseFloat((new RegExp("MSIE ([0-9]{1,}[.0-9]{0,})")).exec(navigator.userAgent)[1]):-1;}

$(document).ready(function(){
 var IEv = vIE();
 if (IEv > 0)
 $('iframe').attr({allowTransparency : "true"});
});