Thus, Loffland pleaded and established a valid and subsisting debt against Overstreet, under this State's laws.Hedlund v. Brogan, 167 Okla. 393, 30 P.2d 164 (1934); Reeves v. Jenkins, 439 P.2d 941 (Okla. 1968). Loffland's petition did not expressly request pre-judgment interest.