allow access to single .aspx page?

Currently I am restricting acces to my site using forms in the web.config file but I want to also allow access to a single page? How do I do this?

Here is my current web.config:

<system.web>
<authentication mode="Forms" />
<authorization>
      <deny users="?"/>
      <allow users="*"/>
</authorization>
</system.web>