function processNumber(enrollment) {
    try {
        var inpVal = parseInt(enrollment.value, 10);
        if (isNaN(inpVal) || inpVal == "0") {
            var msg = "رقم السجل خطأ \n Enrolement must be a number.";
            var err = new Error(msg);
            if (!err.message) {
                err.message = msg;
            }
            throw err;
        }
    } catch (e) {
        alert(e.message);
        enrollment.focus();
        enrollment.select();
    }
}