title: how to test a string for letters only
body: <p>how could I test a string against only valid characters like letters a-z?...</p>
  
  <pre><code>string name;
  
  cout &lt;&lt; "Enter your name"
  cin &gt;&gt; name;
  
  string letters = "qwertyuiopasdfghjklzxcvbnm";
  
  string::iterator it;
  
  for(it = name.begin(); it = name.end(); it++)
  {
    size_t found = letters.find(it);
  }
  </code></pre>