Is is possible to change the body class within iFrame's source HTML?
Obviously the code below is not functional, it is for example only. I have tried several ideas but nothing I try seems to work.

Many thanks for any advice.

<pre id=code><font face=courier size=2 id=code>
&lt;head&gt;
&lt;style&gt;
.blue { background-color: blue; color: yellow; }
&lt;/style&gt;
&lt;/head&gt;
&lt;body&gt;
&lt;iframe src="iframetest.htm" name="myiframe" width="200" height="300"&gt;&lt;/iframe&gt;

&lt;input type="button" name="Blue" value="Blue" onClick="document.body.myiframe.document.body.className='blue'"&gt;
&lt;/body&gt; </font id=code></pre id=code>

Hi

Try this out. I always use to call a function in the IFRAME source document in order to get access to the DOM.

Put this function in the document that holds the IFRAME.

function hookToIframeDoc(){
document.frames("YOUR_FRAME".alterFrameDoc(); //calls a function place in the IFRAME source document
}

Function placed in the IFRAME source document

function alterFrameDoc(){
document.body.style.backgroundColor = "whitesmoke";
}

<BLOCKQUOTE id=quote><font size=1 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>
Hi

Try this out. I always use to call a function in the IFRAME source document in order to get access to the DOM.

Put this function in the document that holds the IFRAME.

function hookToIframeDoc(){
document.frames("YOUR_FRAME".alterFrameDoc(); //calls a function place in the IFRAME source document
}

Function placed in the IFRAME source document

function alterFrameDoc(){
document.body.style.backgroundColor = "whitesmoke";
}
<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

Awesome!
Thanks for you help Peter, much appreciated!