We observe that the motion to dismiss filed on April 14, 1962, aside from disputing the lower courts jurisdiction over defendants person, prayed for dismissal of the complaint on the ground that plaintiffs cause of action has prescribed. By interposing such second ground in its motion to dismiss, Ker and Co., Ltd. availed of an affirmative defense on the basis of which it prayed the court to resolve controversy in its favor. For the court to validly decide the said plea of defendant Ker & Co., Ltd., it necessarily had to acquire jurisdiction upon the latters person, who, being the proponent of the affirmative defense, should be deemed to have abandoned its special appearance and voluntarily submitted itself to the jurisdiction of the court. Similarly, the case of De Midgely vs. Ferandos, held that: When the appearance is by motion for the purpose of objecting to the jurisdiction of the court over the person, it must be for the sole and separate purpose of objecting to the jurisdiction of the court. If his motion is for any other purpose than to object to the jurisdiction of the court over his person, he thereby submits himself to the jurisdiction of the court. A special appearance by motion made for the purpose of objecting to the jurisdiction of the court over the person will be held to be a general appearance, if the party in said motion should, for example, ask for a dismissal of the action upon the further ground that the court had no jurisdiction over the subject matter.lii[52] Clearly, petitioner had submitted to the jurisdiction of the Regional Trial Court of Quezon City. Thus, we find that the trial court has jurisdiction over the case and that its exercise thereof, justified. As to the choice of applicable law, we note that choice-of-law problems seek to answer two important questions: (1) What legal system should control a given situation where some of the significant facts occurred in two or more states; and (2) to what extent should the chosen legal system regulate the situation.liii[53] Several theories have been propounded in order to identify the legal system that should ultimately control. Although ideally, all choice-of-law theories should intrinsically advance both notions of justice and predictability, they do not always do so. The forum is then faced with the problem of deciding which of these two important values should be stressed.liv[54] Before a choice can be made, it is necessary for us to determine under what category a certain set of facts or rules fall. This process is known as characterization, or the doctrine of qualification. It is the process of deciding whether or not the facts relate to the kind of question specified in a conflicts rule.lv[55] The purpose of characterization is to enable the forum to select the proper law.lvi[56] Our starting point of analysis here is not a legal relation, but a factual situation, event, or operative fact.lvii[57] An essential element of conflict rules is the indication of a test or