var preloadFlag = false;
var timer = new Object();
var speedMultiplier = 1;

function changeMenuImages(nameMenu, action) {
    if (preloadFlag) {
        if(document.getElementById) {
            if(action == 'out') {
                timer.changeImages = setTimeout(function () {document.getElementById('menu_image').src = '/images/menu_' + currentPage + '.gif';}, 150);
            } // action == 'over'
            else {
                clearTimeout(timer.changeImages);
                document.getElementById('menu_image').src = '/images/menu_' + nameMenu + '.gif';
            }
        }
    }
}

function preloadImages(arg) {
    if (document.images) {
        for(var i = 0; i < preloadImages.arguments.length; i++) {
            if (document.images) {
                rslt = new Image();
                rslt.src = preloadImages.arguments[i];
            }
        }
        preloadFlag = true;
    }
}

function scroll(dir) {
    clearTimeout(timer.scroll);
    if(dir == 'stop') {
        if(preloadFlag) {
            document.getElementById('scrollUp').src = '/images/scroll_up_normal.gif';
            document.getElementById('scrollDown').src = '/images/scroll_down_normal.gif';
            speedMultiplier = 1;
        }
        return;
    }

    var scrollStep =  Math.ceil(2 * speedMultiplier / 50);
    if (preloadFlag && dir == 'Up') {
        document.getElementById('scroll' + dir).src = '/images/scroll_up_hover.gif';
        document.getElementById('content').scrollTop -= scrollStep;
    }
    else if(preloadFlag && dir == 'Down') {
        document.getElementById('scroll' + dir).src = '/images/scroll_down_hover.gif';
        document.getElementById('content').scrollTop += scrollStep;
    }
    if(speedMultiplier < 300) {
        speedMultiplier++;
    }
    timer.scroll = window.setTimeout("scroll('" + dir + "')", 1000 / 75);
}

function scrollInit() {
    var bt = document.getElementById('scrollButtons');
    var content = document.getElementById('content');
    bt.style.display = 'none';// (content.scrollHeight - content.clientHeight > 0) ? 'block' : 'none';
}

function changeNavImages(action) {
    if(preloadFlag) {
        if(action == 'out') {
            document.getElementById('navBack').src = '/images/arrow_back_normal.gif';
        }
        else {
            document.getElementById('navBack').src = '/images/arrow_back_hover.gif';
        }
    }
}

function clearField(field, arg, action) {
    if(action == 'focus') {
        var pattern = new RegExp(arg);
        if(pattern.test(field.value)) {
            field.value = '';
        }
    }
    else {
        var pattern = new RegExp("\\S");
        if(!pattern.test(field.value)) {
            field.value = arg;
        }
    }
    return;
}