It has recently teen shown that discontinuous functional calculi exist for certain commutative Banach algebras. Such an algebra thus possesses two distinct calculi so that there exist analytic functions whose action on the algebra is not uniquely determined.In this note a method is given for constructing commutative Banach algebras which admit two inequivalent complete norm topologies and the result is applied to show that the action of any non-algebraic analytic function may fail to be uniquely defined.The purpose of this paper is to give a simple method for constructing commutative Banach algebras which have non-unique complete norm topology.One of the first examples of such an algebra was that of Feldman (see [J], an example originally constructed to show the failure of the Wedderburn Theorem. This algebra is £" @ C as a vector space with the usual product in lp and trivial multiplication by the second summand, and has a norm in which V is dense. Thus in a sense I has been completed by the adjunction of a radical and the resulting algebra has the non-uniquenessproperty. This is the idea exploited herein, and although the norm of the Feldman example is not obtainable by our approach other inequivalent norms on Z 2 © C may be constructed. Indeed this is essentially done in [I].