How Do My App Know Which Membership Provider To Use

Hi, I read these links:
http://forums.asp.net/p/1029854/1412044.aspx#1412044

http://forums.asp.net/p/1380518/2917622.aspx#2917622

My question is: How do I instruct my application to use membership with requiresQuestionAndAnswer="false" if a user logged in with administrator role who wants to reset password for another user? How does one config/thing tie to another?
Thanks.
Garreth

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