/**
 * Runs through the DOM under the element with the given id, finds all
 * checkboxes and sets them to the wanted state.
 *
 * @param String
 *            id Id of the element containing all the checkboxes
 * @param Boolean
 *            checked True if the checkboxes should be checked
 */
function checkAll(id, checked) {
    var obj = document.getElementById(id);
    var boxes = obj.getElementsByTagName("input");
    for (var i = 0; i < boxes.length; i++) {
        if (boxes[i].type === "checkbox" && !boxes[i].disabled) {
            boxes[i].checked = checked;
        }
    }
}

$(function () {
    /**
     * Disable every submit button after clicking (to prevent double-clicking)
     */
    $("form").submit(function (ev) {
        $("input[type='submit']").prop("readonly", true).addClass("disabled");
        return true;
    });
});