// Zip Code
    if (fieldZip == "") {
        alertForZip.innerHTML = alertMessage;
    }
    else if (fieldZip.length <= 4 || fieldZip.length >= 11) {
        alertForZip.innerHTML = "<p>WRONG</p>";
    }

    function returnCurrentValue(input) {
        let inputValue = input.value;
        let zipCodePattern = /^\d{5}$|^\d{5}-\d{4}$/;
        if(zipCodePattern.test(inputValue)) {
            // do something if everythink is legit
        } else {
            alertForZip.innerHTML = "<p>WRONG</p>";
        }
    }