var input = document.querySelector("#phone"), errorMsg = document.querySelector("#error-msg"), validMsg = document.querySelector("#valid-msg"); // here, the index maps to the error code returned from getValidationError - see readme var errorMap = [ "Invalid number", "Invalid country code", "Too short", "Too long", "Invalid number"]; // initialise plugin var iti = window.intlTelInput(input, { utilsScript: "../../build/js/utils.js?1541153396801" }); var reset = function() { input.classList.remove("error"); errorMsg.innerHTML = ""; errorMsg.classList.add("hide"); validMsg.classList.add("hide"); }; // on blur: validate input.addEventListener('blur', function() { reset(); if (input.value.trim()) { if (iti.isValidNumber()) { validMsg.classList.remove("hide"); } else { input.classList.add("error"); var errorCode = iti.getValidationError(); errorMsg.innerHTML = errorMap[errorCode]; errorMsg.classList.remove("hide"); } } }); // on keyup / change flag: reset input.addEventListener('change', reset); input.addEventListener('keyup', reset);