title: How to modify this JavaScript regex to check for a person's valid name?
body: <p>This JavaScript regex checks to see if a person has entered a valid username:</p>
  
  <pre><code>var regexp = "/^[a-z]([0-9a-z])+$/i";
  if(!regexp.test(name)) 
    return "Name may consist of letter, numbers and start with a letter." );
  </code></pre>
  
  <p>But I want to check whether the person has entered a valid name.</p>
  
  <p>In other words:</p>
  
  <pre>
  Cher
  Michael Jackson
  Mary J. Blige
  François Truffaut
  </pre>
  
  <p>I can't think of any cases where anything other than letters and maybe a period would be valid in a person's name. </p>
  
  <p>I want to reject any other types of punctuation as a validation mistake.</p>
  
  <p>But I want to make sure that, for example, <code>François Truffaut</code> would not be rejected because he has that funny version of the letter c that the French use.</p>
  
  <p>How would I do this in a Javascript regex</p>