Your friend is wrong, and here is why:
The word 'of' is a prepostition, which is "a function word that typically combines with a noun phrase to form a phrase which usually expresses a modification or predication." [1] You see, "of" needs to come before another phrase which modifies the preceding phrase. Your friend has made a "dangling prepostiion" [2] which is syntactically incorrect.
[1]
http://www.m-w.com/cgi-bin/dictionary?va=preposition
[2]
http://www.cs.utexas.edu/users/rprie...links/prep.htm