osx - Turning on syntax highlighting in vim causes warning message -

i'm wanting turn on syntax highlighting in vim using .exrc file , using following commands:

syntax on syntax=html 

every time open file following message now:

no syntax items defined buffer

i'm using vim version 7.3 on os x 10.10.4

use following in ~/.vimrc file:

filetype plugin indent on syntax on 

for more information see:

:h :filetype :h :syntax :h filetype