//http://www.webreference.com/programming/javascript/onloads/
function addLoadEvent(func) {
    var oldonload = window.onload;
    if (typeof window.onload != 'function') {
        window.onload = func;
    } else {
        window.onload = function() {
            if (oldonload) {
                oldonload();
            }
            func();
        };
    }
}
//http://www.quirksmode.org/dom/getstyles.html
function getStyle(el, styleProp) {
    var x = document.getElementById(el);
    if (x.currentStyle)
        return x.currentStyle[styleProp];
    else if (window.getComputedStyle)
        return document.defaultView.getComputedStyle(x, null).getPropertyValue(styleProp);
}

//http://www.quirksmode.org/js/cookies.html
function createCookie(name, value, days) {
    if (days) {
        var date = new Date();
        date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000));
        var expires = "; expires=" + date.toGMTString();
    }
    else var expires = "";
    document.cookie = name + "=" + value + expires + "; path=/";
}
function readCookie(name) {
    var nameEQ = name + "=";
    var ca = document.cookie.split(';');
    for (var i = 0; i < ca.length; i++) {
        var c = ca[i];
        while (c.charAt(0) == ' ') c = c.substring(1, c.length);
        if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length, c.length);
    }
    return null;
}

function eraseCookie(name) {
    createCookie(name, "", -1);
}


function setOpc(img, opc) {
    img.style.MozOpacity = opc / 100;
    img.style.opacity = opc / 100;
    img.style.filter = 'alpha(opacity=' + opc + ')';
}