 The pressure usually emanates from a close or fiduciary relationship in which one party abuses a superior position to influence the other.To set aside a contract on the ground of undue influence, the party so affected must establish that the other party obtained an influence over him, that this influence weakened his powers of resistance and rendered his will compliant, and that the other party used this influence in an unscrupulous manner to induce an agreement that he would not have concluded with normal freedom of will.