title: Masking input with optional alphabet prefix to a phone number format
body: <p>I know of this nice jquery plugin: <a href="http://digitalbush.com/projects/masked-input-plugin/" rel="nofollow">http://digitalbush.com/projects/masked-input-plugin/</a>
  for Masked input, and I can use it fine.</p>
  
  <p>So let's say I want a field to be masked by this format: <code>+999 9 999 9999</code>
  That's fine, and it's working.</p>
  
  <p>The issue is that sometimes within the field, my users also have the option of giving some text before the number.</p>
  
  <p>So the two inputs that are valid for a user are: </p>
  
  <ul>
  <li><code>+999</code> <code>9</code> <code>999</code> <code>9999</code></li>
  <li><code>any optional alphabet letters and special characters (but not digits!)</code> <code>+999</code> <code>9</code> <code>999</code> <code>9999</code>,</li>
  </ul>
  
  <p>So for example, this is a valid user input: <code>+966 1 484 1122</code>. </p>
  
  <p>And this is also a valid user input: <code>Phone #: +966 1 484 1122</code>. </p>
  
  <p>How can I make this mask?</p>
  
  <h2>Edit</h2>
  
  <p>For the second type of input, there are actually a finite number of alphabetical prefixes possible, like these:</p>
  
  <ul>
  <li>Phone: +999 9 999 9999</li>
  <li>Phone +999 9 999 9999</li>
  <li>Phone # +999 9 999 9999</li>
  <li>Phone #: +999 9 999 9999</li>
  <li>Call: +999 9 999 9999</li>
  <li>Call me: +999 9 999 9999</li>
  <li>Call +999 9 999 9999</li>
  <li>Telephone +999 9 999 9999</li>
  <li>Telephone # +999 9 999 9999</li>
  <li>Telephone: +999 9 999 9999</li>
  <li>Talk +999 9 999 9999</li>
  <li>Contact: +999 9 999 9999</li>
  <li>Contact # +999 9 999 9999</li>
  <li>Contact #: +999 9 999 9999</li>
  </ul>
  
  <p>Basically, just the usual possible ways of telling users to "call" at a given number. For this problem, let's assume the prefix can only be the above words. So that means the format for the prefix is usually <code>Call|Contact|Talk|Phone|Telephone</code>, <code>optional #</code>, <code>optional :</code>.</p>
  
  <p>And the overall mask is something like:
  <code>optional Call|Contact|Talk|Phone|Telephone</code> <code>optional #</code> <code>optional :</code> <code>+999 9 999 9999</code></p>