how to change an iframe with button rollover

[DesignerNic]

Is it possible to change an iframes content by rolling over a button (not clicking?) I don't know how to write the JS for this.

thank you!!

[molendijk]

<iframe name="my_iframe" src="http://www.google.com"></iframe>
<br>
<button onmouseover="window.frames.my_iframe.window.location.replace('http://www.dynamicdrive.com')">dynamicdrive</button>
<button onmouseover="window.frames.my_iframe.window.location.replace('http://www.google.com')">google</button>

Arie Molendijk.