Authentification

Hi friends.

I implemeted the authentification in my site.
So only one domain group has access to the homepage.
But every one in this group must logon on the site.

How i can pass the autenthification automatically wthout any logon window? (Its only an intranetsite).
Thats what i have:
<authentication mode="Windows"/>
    <anonymousIdentification enabled="true"/>
    
    <authorization>
      
      <allow roles="domain\goup" />
      <deny users="*"/>
      
    </authorization>
...