DALLAS — Toys 'R' Us has tapped Atlanta-based IDI to develop a 825,000 sq. ft., $32 million distribution center in the Railport Regional Distribution Center in Midlothian, Texas, outside Dallas. James N. Gray Co., Lexington, Ky., will be the contractor, and St. Louis-based CASCO Corp. designed the building. The distribution center is scheduled to be completed in July 2001.