airExpressApp.directive(‘validateDecimalCharacters‘, function () {    var REQUIRED_PATTERNS = [      /^-?[0-9]\d*(\.\d+)?$/    ];    return {        require: ‘ngModel‘,        link: function ($scope, element, attributes, ngModelController) {            ngModelController.$validators.validateDecimalCharacters = function (modelValue, viewValue) {                var status = true;                if (!ngModelController.$isEmpty(modelValue)) {                    angular.forEach(REQUIRED_PATTERNS, function (pattern) {                        status = status && pattern.test(modelValue);                    });                }                return status;            };        }    }});