Party must prove his affirmative allegations.
Section 297
SEC. 297. Party must prove his affirmative allegations. — Each party must prove his own affirmative allegations. Evidence need not be given in support of a negative allegation except when such negative allegation is essential part of the statement of the right or title on which the cause of action or defense is founded, nor even in such case when the allegation is a denial of the existence of a document the custody of which belongs to the opposite party.