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There a several changes that need to be made to the web.config file to use the built in membership system. You can see these on thethe Manual Installation page. These are standard configuration elements for ASP,Net Membership. One key attribute is on the <add name="LightweightMembershipProvider"...> tag, the attribute is 'initPassword' and this value is used as the password for any user who has a null password field.
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The membership system features an extensible User type. This can be extended as described in the Extend a Type section. This allows the client code to add extra fields into the membership record.
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