Auto update last modified user/time vim script

From Tip #890: Last modified: <CURRENT DATETIME>

" Search the first 8 lines for Last Updated: and update the current user/datetime
function! LastMod()
　if &modified
　　if line("$") > 8
　　　let l = 8
　　else
　　　let l = line("$")
　　endif
　　let time = strftime("%m\\\/%d, %Y")
　　exe "1," . l . "g/Last Updated: /s/Last Updated: .*/Last Updated: yyhuang " . time . "/"
　　endif
endfun

" This autocommand will call LastMod function everytime you save a file
autocmd BufWrite * ks|call LastMod()|'s