Clairton Corporation (plaintiff) rented a commercial building to Geo-Con, Inc. (defendant) for a period of two years. At the end of the two-year term, the parties were discussing a new lease under which Geo-Con would rent more space. Ultimately, the parties did not come to a formal agreement on a new lease. Rather, Geo-Con, with Clairton’s consent, simply continued to possess the leased premises, paying the same monthly rent that was due under the expired lease. After seven months, Geo-Con vacated the premises and stopped paying rent. Clairton brought suit, claiming that Geo-Con’s holdover tenancy must last for one full year. Clairton thus sought rent for the remaining five months of that term. Geo-Con argued that when the original lease expired it had become a month-to-month tenant. The trial court ruled that Geo-Con had become a month-to-month tenant. Clairton appealed.