// Converting functions to Namespace Notation

var Sdk = window.Sdk || {};

(

    function () {

        this.formOnLoad = function (executionContext) {

        };

        this.MailPhoneOnChange = function (executionContext) {

            var formContext = executionContext.getFormContext();

            var phoneNumber = formContext.getAttribute("telephone1").getValue();

            var expression = new RegExp("/^[\+]?[(]?[0-9]{3}[)]?[-\s\.]?[0-9]{3}[-\s\.]?[0-9]{4,6}$/im");

            if (!expression.test(phoneNumber)) {

                alert("The phone number entered should use correct format");

            }

        };

    }

).call(Sdk);