radius-apache authentication problem

Hi I want to implement otp authentication for a web site. Radius and otp scripts works well together but apache don't send any authentication data to radius. I followed instructions in http://www.freeradius.org/mod_auth_radius/ but apache mod_authn_file wants passwords and could not be disabled. when i removed the module no authn provider configured are seen in apache error logs. Changing AuthBasicAuthorative on or off in .htaccess didn't solve the problem. Problem stems from apache but someone solves such a problem can respond me.