using radius: newbie

i would like to use gnu-radius to authenticate a user of a wireless  
access point.  the access point is a router/switch which can pass out  
ip address.  what i would like to do is have anyone that tries to get  
online first goto a web site where they would enter some information  
and then after entering the info, they maybe given access to the  
internet.  is this possible using gnu radius server?

thanks,

g.