Greeting's

I am trying to run softeware on Cygwin. I am having problems with Nmap. I do get to the folder where I have unzipped Nmap but then when I type "Nmap" or the entire syntex of nmap (E.g. = nmap -sS -P0 -O 123.123.132.321) I get an error saying NMAP COMMAND NOT FOUND. I went to Nmap's site (www.insecure.org) but very little information is given on how to run Nmap on Cygwin system. Any help will be appriciated.