Authentication Question

Hi, I'm pretty new to freeradius and need some help. In Freeradius, when a request is made can you used the supplied userid and password to authenticate off from LDAP and if the user does not exist in LDAP can force it to authenticate off from the local database? If this is possible, can you direct me to some links that can further assist me. Thanks in advance ... __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com