function makeSublist(parent,child,isSubselectOptional,childVal)
{
    $("body").append("<select style='display:none' id='"+parent+child+"'></select>");
    $('#'+parent+child).html($("#"+child+" option"));

    var parentValue = $('#'+parent).attr('value');
    $('#'+child).html($("#"+parent+child+" .sub_"+parentValue).clone());

    childVal = (typeof childVal == "undefined")? "" : childVal ;
    $("#"+child+' option[value="'+ childVal +'"]').attr('selected','selected');

    $('#'+parent).change(
        function()
        {
            var parentValue = $('#'+parent).attr('value');
            $('#'+child).html($("#"+parent+child+" .sub_"+parentValue).clone());
            if(isSubselectOptional) $('#'+child).prepend("<option value='none'> -- prosím vyberte -- </option>");
            $('#'+child).trigger("change");
            $('#'+child).focus();
        }
        );
}