function newImage(arg) {
    if (document.images) {
        rslt = new Image();
        rslt.src = arg;
        return rslt;
    }
}

function changeImages() {
    if (document.images && (preloadFlag == true)) {
        for (var i=0; i<changeImages.arguments.length; i+=2) {
            document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
        }
    }
}

var preloadFlag = false;
function preloadImages() {
    if (document.images) {
        index_17_over = newImage("zdj/indexn_17-over.jpg");
        index_18_over = newImage("zdj/indexn_18-over.jpg");
        index_19_over = newImage("zdj/indexn_19-over.jpg");
        index_20_over = newImage("zdj/indexn_20-over.jpg");
        index_21_over = newImage("zdj/indexn_21-over.jpg");
        preloadFlag = true;
    }
}


function displayWindow(url, width, height) {
        var Win = window.open(url,"displayWindow",'width=' + width + ',height=' + height + ',resizable=0,scrollbars=no,menubar=no,left=0,top=0');
}