title: Jquery find credit card type
body: <p>I found this simple function to return the 4 most common credit card types.</p>
  
  <p>Being new to jQuery, what jQuery plugin can I use to display the credit card type as a user types in a credit card number in a input field?</p>
  
  <pre><code> function creditCardTypeFromNumber(num) {
     // first, sanitize the number by removing all non-digit characters.
     num = num.replace(/[^\d]/g,'');
     // now test the number against some regexes to figure out the card type.
     if (num.match(/^5[1-5]\d{14}$/)) {
       return 'MasterCard';
     } else if (num.match(/^4\d{15}/) || num.match(/^4\d{12}/)) {
       return 'Visa';
     } else if (num.match(/^3[47]\d{13}/)) {
       return 'AmEx';
     } else if (num.match(/^6011\d{12}/)) {
       return 'Discover';
     }
     return 'UNKNOWN';
   }
  </code></pre>
  
  <p>Thank you!</p>