emmet dos not work

Hello, 
I installing emmet with zip file & add this code:
`let g:user_emmet_mode='n'    "only enable normal mode functions.
`
`
let g:user_emmet_mode='inv'  "enable all functions, which is equal to
`
`
let g:user_emmet_mode='a'    "enable all function in all mode.
`
& dose not work emmet,help me please.
