const iframe = document.getElementById("myIframe");
const iWindow = iframe.contentWindow;
const iDocument = iWindow.document;
// accessing the element
const element = iDocument.getElementsByTagName("p")[0];
element.style.color = "green";<iframe id="myIFrame" src="thispage.html"
width="100%" height="600"
frameBorder="2">
</iframe>
// Get the iframe
const iFrame = document.getElementById('myIFrame');
// Let's say that you want to access a button with the ID `'myButton'`,
// you can access via the following code:
const buttonInIFrame = iFrame.contentWindow.document.getElementById('myButton');
// If you need to call a function in the iframe, you can call it as follows:
iFrame.contentWindow.yourFunction();<script type="text/javascript">
function iframeDidLoad() {
alert('Done');
}
function newSite() {
var sites = ['http://getprismatic.com',
'http://gizmodo.com/',
'http://lifehacker.com/']
document.getElementById('myIframe').src = sites[Math.floor(Math.random() * sites.length)];
}
</script>
<input type="button" value="Change site" onClick="newSite()" />
<iframe id="myIframe" src="http://getprismatic.com/" onLoad="iframeDidLoad();"></iframe>