How to use the "Masked Input" module in Drupal 7

I am trying to build a form in Drupal 7, one of the fields needs to have an input mask. I found the plugin masked input it seems like what I am searching for . Only there is no documentation on how to implement it (I read about currency and this plugin, yet here it is only about getting it to work).

I am new to Drupal, but searching on forums I came up with the following code:

function report_expenses_form($form, &$form_submit) {
   libraries_get_path('maskedinput') . '/misc/ui/jquery.maskedinput-1.3.js';
 ...
      $form['cash_advance']['amount'] = array(
         '#title' => t('Cash Advance : '),
         '#type' => 'textfield',
         '#default_value' => t('$ 00,00'),
         '#required' => TRUE,
         '#mask' => '$?999.999.999,99',
       );
 ....
 

I installed the "Libraries" and "Masked Input" plugins in Drupal and flushed my caches.

I downloaded the jquery.maskedinput-1.3.js and put it in my {DRUPAL_HOME}/misc/ui/

any Ideas?

thank you in advance

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