An on-board evaporative emission leak detection system and method that detects leakage from an evaporative emission space of a fuel system of an automotive vehicle. The fore-end of the upper fitting arm is fitted to neck ring formed in the lower portion of neck of the bottle and is secured firmly by undercut engagement with the neck ring, and wherein fore-ends of the pair of the lower arms are fitted to bases of a pair of raised portions disposed on both sidewalls of the body of the bottle similarly by the undercut engagement with the raised portions. The mechanism rests on an object-oriented architecture that provides a multiplicity of actions that effects software management operations on the target system.