//    image rollover
function swapImg(elem, keyName) {
    elem.src = _imgArr[keyName];
}


// keypress validation
function getKeyCode(e) {
    if (window.event) {
        return window.event.keyCode;
    } else {
        if (e.keyCode == 0 && typeof (e.which) != 'undefined') {
            return e.which;
        } else {
            return -1;
        }
    }
}

function validateKeyPressAlpha(kCode, allowCase) {
    // valid allowCase argument: UPPER, LOWER, BOTH

    // define valid codes
    var upperMin = 65; // A
    var upperMax = 96; // Z
    var lowerMin = 97; // a
    var lowerMax = 122; // z

    switch (allowCase.toString().toUpperCase()) {
        case "UPPER":
            return (kCode >= upperMin && kCode <= upperMax);
        case "LOWER":
            return (kCode >= lowerMin && kCode <= lowerMax);
        case "BOTH":
            return ((kCode >= upperMin && kCode <= upperMax) || (kCode >= lowerMin && kCode <= lowerMax));
    }
}