While the image is still "Sin City," the reality is that Las Vegas is "Convention City." And the man who makes that work is Steve Hill, CEO and President of the Las Vegas Convention & Visitors Authority.    That's the organization that brings all the huge gatherings to Las Vegas - shows like CES, World of Concrete, the National Association of Broadcasters and countless other smaller events.    The LVCVA is also the region's top marketing arm, and the organization behind "What Happens in Vegas Stays in Vegas." So why did it retire that famous phrase? Steve tells all!   Hosts: Jonathan Jossel, LIsa Melmed, Gary Vickery