form-mask.js

;(function(){
	var $phone = $('.phone');

	var init = function () {
		maskAll();
	};

	var SPMaskBehavior = function (val) {
	  return val.replace(/\D/g, '').length === 11 ? '(00) 00000-0000' : '(00) 0000-00009';
	},
	spOptions = {
	  onKeyPress: function(val, e, field, options) {
	      field.mask(SPMaskBehavior.apply({}, arguments), options);
	    }
	};

	var maskAll = function() {
		$phone.mask(SPMaskBehavior, spOptions);
	}

	$(document)
		.ready(init)
	;
})();