"Novation" is the substitution of a new obligation for an existing one.
§ 28-1-1501, MCA
En. Sec. 2070, Civ. C. 1895; re-en. Sec. 4958, Rev. C. 1907; re-en. Sec. 7460, R.C.M. 1921; Cal. Civ. C. Sec. 1530; Field Civ. C. Sec. 736; re-en. Sec. 7460, R.C.M. 1935; R.C.M. 1947, 58-505.