Can You Give Me A Context Diagram For Hotel Reservation System?

The following link has a Power point presentation with detailed context diagram of hotel reservation system stage wise.

http://www.bit.lk/information/tv/s2/2001/IT2401e.ppt

Another guide could be this link:

http://it.toolbox.com/blogs/about-it-analysis/business-context-diagrams-constructing-the-business-context-diagram-20981

Please write me the contextual diagram of hotel management system