var cookieExpiry = new Date();
fixDate(cookieExpiry);
cookieExpiry.setTime(cookieExpiry.getTime() + 365 * 24 * 60 * 60 * 1000);

function setCookie(name, value, expires, path, domain, secure) {
    var curCookie = name + "=" + escape(value) +
			    ((expires) ? "; expires=" + expires.toGMTString() : "") +
			    ((path) ? "; path=" + path : "") +
			    ((domain) ? "; domain=" + domain : "") +
			    ((secure) ? "; secure" : "");
    document.cookie = curCookie;
}

function getCookie(name) {
    var dc = document.cookie;
    var prefix = name + "=";
    var begin = dc.indexOf("; " + prefix);
    if (begin == -1) {
        begin = dc.indexOf(prefix);
        if (begin != 0) return null;
    }
    else
        begin += 2;
    var end = document.cookie.indexOf(";", begin);
    if (end == -1)
        end = dc.length;
    return unescape(dc.substring(begin + prefix.length, end));
}

function deleteCookie(name, path, domain) {
    if (getCookie(name)) {
        document.cookie = name + "=" +
				    ((path) ? "; path=" + path : "") +
				    ((domain) ? "; domain=" + domain : "") +
				    "; expires=Thu, 01-Jan-70 00:00:01 GMT";
    }
}

function fixDate(date) {
    var base = new Date(0);
    var skew = base.getTime();
    if (skew > 0)
        date.setTime(date.getTime() - skew);
}


function toggleSpan(id, imgid) {
    //alert(document.getElementById(id));
    if (document.getElementById(id) != null) {
        if (document.getElementById(id).style.visibility == 'visible') {
            hideSpan(id, imgid);
            //setCookie(id, '0', cookieExpiry);
            deleteCookie(id);
        }
        else {
            showSpan(id, imgid);
            setCookie(id, '1', cookieExpiry);
        }
    }
}

function initSpan(id, imgid) {
    if (getCookie(id) == '1') {
        showSpan(id, imgid);
    }
    else {
        hideSpan(id, imgid);
    }
}

function showSpan(id, imgid) {
    if (document.getElementById(id) != null) {
        document.getElementById(id).style.visibility = 'visible';
        document.getElementById(id).style.display = 'inline';
        document.getElementById(imgid).src = "minus.gif";
    }
}

function hideSpan(id, imgid) {
    if (document.getElementById(id) != null) {
        document.getElementById(id).style.visibility = 'hidden';
        document.getElementById(id).style.display = 'none';
        document.getElementById(imgid).src = "plus.gif";
    }
}

function preloadImage(filename) {
    img = new Image();
    img.src = filename;
}