[Zope] question about login

I have created a login form an a few users in acl_users, both exists in a ordered folder called conference. My login Form post to a login dtml method and login dtml method redirect me to another page. Even though the user exists and username and password is correct, somehow zope won't redirect me. The login query window pops out three time and in the end it denied me "You are not allowed to access '....' in this context". Can someone help me, is there any thing I have to set?? should I move all the files into the root??