php script – where do I put it

I have added a simple mouseover css class which I think is working but I need to add the script to call on it.

The script is

function setBut(pDiv,pOver) {
if (typeof(pDiv.style) == 'undefined') {
return false;
}
if (pOver) pDiv.className='hover';
else pDiv.className='nohover';
}

but evry time I add it I get php parse errors.

Where should add the script and how ?

Please

Test page : http://www.ozpoker.net.au/private-tournaments/

When done a mouseover the purple banner should call a background image – (wrong image for now – but I just want to see I can get it work)

the mouseover code is
<div onmouseover="setBut(this,1)" onmouseout="setBut(this,0)" onclick="window.location='http://www.ozpoker.net.au/send/vegas247.html'"> <img src="http://www.ozpoker.net.au/banners/vegas247125.gif">
</div>

and I have added that in a html module via nybbles sidebar module

Thanks in advance