function CheckboxSelected() {
    var oneOrMoreChecked = false;
    var checkBoxTable = document.getElementById('checkboxTable');


    var inputs = checkBoxTable.getElementsByTagName('input');
    for (var i = 0; i < inputs.length; i++) {
        if (inputs.item(i).checked) {
            oneOrMoreChecked = true;
        }

    }
    if (!oneOrMoreChecked) { alert('Select one or more article(s) for download.') };
    return oneOrMoreChecked;
}