The invention provides an input device which includes a gripping part, a pointing part, and at least one depressible part furnished in such a manner that while holding the gripping part by hand, a user may manipulate the pointing and depressible parts with fingertips to perform the same kinds of operations as those of a mouse. In one implementation, we provide an identification document comprising a document layer and a first indicium. More specifically, this invention relates to a novel inducible gene expression system and methods of modulating gene expression in a host cell for applications such as gene therapy, large scale production of proteins and antibodies, cell-based high throughput screening assays, functional genomics and regulation of traits in transgenic plants and animals. This allows a software application to auto-diagnose and auto-self-heal any detected faults.