Vim Bda Command to Delete All Buffers

" Bda -  Delete all open buffers.

command! -nargs=0 -bang Bda
    \ :call BufDeleteAll('<bang>')

function! BufDeleteAll(bang)
    let last_buffer = bufnr('$')

    let n = 1
    while n <= last_buffer
        if a:bang == '' && getbufvar(n, '&modified')
            echohl ErrorMsg
            echomsg 'No write since last change for buffer'
                        \ n '(add ! to override)'
            echohl None
            return 0
        endif
        let n = n+1
    endwhile

    let delete_count = 0
    let n = 1
    while n <= last_buffer
        if buflisted(n)
            silent exe 'bdel' . a:bang . ' ' . n
            if ! buflisted(n)
                let delete_count = delete_count+1
            endif
        endif
        let n = n+1
    endwhile

    if delete_count == 1
        echomsg delete_count "buffer deleted"
    elseif delete_count > 1
        echomsg delete_count "buffers deleted"
    endif

endfunction