How to create merkle hash tree of data block

Question

hi friend I want to create an hash tree of my data blocks.I mean I want to create an merkle hash tree of data blocks or files in c# ASP.net.so how to calculet hash of data block so that i can store it in database .I have see
http://www.codeproject.com/KB/recipes/thexcs.aspx this link.not usefull.