Automatically create dir to write file to if it doesn't exist

gistfile1.vim

" Automatically create dir to write file to if it doesn't exist
function! AutoMkDir()
    let required_dir = expand("<afile>:p:h")
    if !isdirectory(required_dir)
        if confirm("Directory '" . required_dir . "' doesn't exist.", "&Abort\n&Create it") != 2
            bdelete
            return
        endif

        try
            call mkdir(required_dir, 'p')
        catch
            if confirm("Can't create '" . required_dir . "'", "&Abort\n&Continue anyway") != 2
                bdelete
                return
            endif
        endtry
    endif
endfunction
autocmd BufNewFile,BufWritePre * call AutoMkDir()