function checkString(thisField, nextField) {
    document.getElementById(thisField).value = document.getElementById(thisField).value.toUpperCase();
    if (nextField != null) {
        if (document.getElementById(thisField).value.length == 4) { document.getElementById(nextField).focus(); }
    }
}
function clearField(thisField) {
    document.getElementById(thisField).value = '';
}
function setUpperRightHeight() {
    var UpperRightHeight = document.getElementById('UpperRight').offsetHeight;
    var LowerRightHeight = document.getElementById('LowerRight').offsetHeight;
    var UpperLeftHeight = document.getElementById('UpperLeft').offsetHeight;
    
    if ((UpperRightHeight + LowerRightHeight) < UpperLeftHeight) {
        document.getElementById('UpperRight').style.height = UpperLeftHeight - LowerRightHeight + 'px';
    }
}