true if the update was successful; otherwise, false.
MembershipUser.ChangePassword(string, string) calls the MembershipProvider.ChangePassword(string, string, string) method of the membership provider referenced by the MembershipUser.ProviderName property to update the password for the membership user in the membership data store.
The membership provider may have restrictions on the size of the password. For size limitations, see the documentation for the membership provider.