title: VIM: omnicomplete, autoselect first item in dropdown-box
body: <p>standard for VIM complete is to select the first item in the dropdown-box (and select the desired entry with up and down).
  i rather type on till the correct entry is the only one available.</p>
  
  <p>this is done by:</p>
  
  <pre>
  set completeopt=longest,menuone 
  </pre>
  
  <p>problem: now i have to manually press  to select the entry.</p>
  
  <p>there is a mapping which simulates  when the menu is open:</p>
  
  <pre>
  inoremap   pumvisible() ? '' : 
    \ '=pumvisible() ? "\Down>" : ""' 
  
  inoremap   pumvisible() ? '' : 
    \ '=pumvisible() ? "\Down>" : ""' 
  </pre>
  
  <p>vim.wikia.com/wiki/VimTip1386 </p>
  
  <p>but it doesnt work for me. just does nothing.
  any idea?</p>
  
  <p>(vim 7.2, win xp)</p>