Auto-scroll textarea in iframe

Question

So basically I have this Iframe

<iframe src ="http://.../iframe.php" id="myIframe"></iframe>

and the only thing on this iframe page (iframe.php) is a textarea:

<textarea  id="test" name="text" rows="20" cols="50" readonly> 

I tried scrolling the textarea down if the value of the textarea exceeds the iframe window (on the page with the Iframe on it) but it just wont work. I tried a few solutions on stackoverflow but nothing worked for me.

UPDATE

It's working now. Working code if everyone is interested:

function myFunctiontest() {
 var goddammit = document.getElementById('myIframe').contentWindow.document.getElementById('test');
     goddammit.scrollTop = goddammit.scrollHeight;
        }

Answer 1

Try oninput="this.scrollTop = this.scrollHeight;" in the textarea and if it works do it properly with the event handler.

Update:

In the page that contains the <iframe> , it has an id as well as the textarea:

window.onload = function () {

    var ifr = document.getElementById('ifr'),
        ta = ifr.contentDocument.getElementById('ta');

    ta.scrollTop = ta.scrollHeight; 

}