iframe overflow

HTML

<div><iframe scrolling="auto" src="http://www.w3.org"></iframe></div>

CSS

div {
    /*width: 480px;
    height: 320px;*/
    padding: 0;
    /*overflow: auto;*/
    background: blue;
}
iframe {
    /*display: block;*/
    /*vertical-align: bottom;*/
    width: 100%;
    height: 4000px;
    margin: 0;
    padding: 0;
    border: 0 none;
    overflow:auto;
    
}