title: Stripe.validateCardNumber not returning true
body: <p>I am currently working on a checkout form, using Stripe as the payment gateway. I am using Stripe.js client side validation functions to verify card information input. The problem is that I can't seem to get the functions to return true, even while inputting values that should return true, such as 4242424242424242. </p>
  
  <p>Here is a relevant snippet of code:</p>
  
  <pre><code>var error=false;
  
  var cc_number=$('#cc_number').val(),
      cc_exp_month=$('#cc_exp_month').val(),
      cc_exp_year=$('#cc_exp_year').val(),
      cc_cvc=$('#cc_cvc').val();
  
  $('#cc_number_error').hide();
  $('#cc_exp_error').hide();
  $('#cc_cvc_error').hide();
  
  $('#cc_number').keyup(function(){
      if(!Stripe.validateCardNumber(cc_number)){
          error=true;
          $('#cc_number_error').show();
      }
      else{
          error=false;
          $('#cc_number_error').hide();
      }
      $('.address_f_name').val(error);
  });
  </code></pre>
  
  <p>I can always manage to get the validation methods to return false, but never true.</p>
  
  <p>There is definitely a possibility that there is something wrong with my code, as I am a beginner in programming. Any help would be appreciated. Thanks!</p>