The owners and developers of the JW Marriott Hotel in Cherry Creek have turned their sights to the edge of downtown Denver where they plan to build condominiums aimed at young professionals buying their first homes.  Grant Park which will stand eight stories with 112 units will be located at the southwest corner of Grant Street and East 20th Avenue in the Uptown neighborhood.  The market-rate units will be priced from about $180,000 to $300,000.  The city requires that at least 10 percent of them be affordable, meaning they will cost less.  Units will range in size from about 850 square feet to 1,100 square feet.  (Source: Rocky Mountain News 07/07/05)