No person driving or in charge of a motor vehicle shall permit it to stand unattended without stopping the engine, locking the ignition, removing the key from the ignition, effectively setting the brake thereon and, when standing upon any perceptible grade, turning the front wheels to the curb or side of the highway.
(ILCS Ch. 625, Act 5, § 11-1401) (`95 Code, § 72.02) Penalty, see § 72.99