query regarding illeagal contract

CA Neeraj Bansal (credit manager of icici bank)   (109 Points)

29 December 2007  
1. colleteral contract related with an illeagal contract is void, but is it also illeagal?

2.If a bus is there standing at a bus stand ,is it giving offer for contract or is it an invitation for offer.

Plz Confirm me same and oblige