Bit unsure what you're trying to accomplish but I'll take a crack:
If you want to refresh your game from within your iFrame, that's as simple as restart layout event, you can map this from everything from a collision to a key press.
Refreshing your game from outside the iFrame, via a text or image link is pretty simple: Your best bet is to simply refresh the whole page, which will reset the iFrame.
If you want to refresh the game without refreshing your web-page, in theory you could get creative with mouse overlapping collisions; with your game refreshing the layout whenever the mouse isn't within your iFrame: The practicality of this questionable though.
Finally, if your familiar with JS, you can use that refresh your frame, simply use this on a button on your parent page:
[CODE]<IFRAME id="frame1" src="http://www.example.com/" runat="server">
<asp:Button ... OnClientClick="refreshiframe();" />[/CODE]
I'm pretty sure you can refresh an iFrame simply in HTML, though I've never tried, doubtless someone knows!