Conversion actions must be commenced no later than two years after the day the cause of action accrues. Tex. Civ. Prac. & Rem. Code Ann. 16.003(a) (Vernon 1997). The question of when a cause of action accrues is a judicial one, to be determined "with due regard to the underlying statutory policy of repose, without, however, permitting unnecessary individual injustices." Moreno v. Sterling Drug, Inc., 787 S.W.2d 348, 351 (Tex. 1990). The objective of statutes of limitation is to compel the assertion of claims within a reasonable period of time, while the evidence is fresh in the minds of the parties and witnesses. Computer Assoc. Int'l, Inc. v. Altai, Inc., 918 S.W.2d 453, 455 (Tex. 1996). In conversion cases, the general rule is that limitations begin to run at the time of the unlawful taking. Rogers v. Ricane Enter., Inc., 930 S.W.2d 157, 166 (Tex.App.--Amarillo 1996, writ denied). However, if the original possession is lawful, the limitation period does not begin to run until the return of the property has been demanded and refused, or until the person in possession has unequivocally exercised acts of domination over the property inconsistent with the claims of the owner or the person entitled to possession. Id. at 166.