title: trouble in using git commit -m
body: <p>When running <code>git commit -m "Commit message"</code> It returns the error message:</p>
  
  <blockquote>
    <p>fatal: empty ident name (for ((null))) not allowed</p>
  </blockquote>
  
  <p>and then asks for the account's default identity.</p>
  
  <p>See the <a href="http://i.stack.imgur.com/tyoPC.png" rel="noreferrer">command prompt screenshot </a> for more details.</p>