function setElementOpacity(oElem, nOpacity) {
    var p = getOpacityProperty();
    (setElementOpacity = p == "filter" ? new Function('oElem', 'nOpacity', 'nOpacity *= 100;    var oAlpha = oElem.filters["DXImageTransform.Microsoft.alpha"] || oElem.filters.alpha;    if (oAlpha) oAlpha.opacity = nOpacity; else oElem.style.filter += "progid:DXImageTransform.Microsoft.Alpha(opacity="+nOpacity+")";') : p ? new Function('oElem', 'nOpacity', 'oElem.style.' + p + ' = nOpacity;') : new Function)(oElem, nOpacity);
}

function getOpacityProperty() {
    var p;
    if (typeof document.body.style.opacity == 'string') p = 'opacity';
    else if (typeof document.body.style.MozOpacity == 'string') p = 'MozOpacity';
    else if (typeof document.body.style.KhtmlOpacity == 'string') p = 'KhtmlOpacity';
    else if (document.body.filters && navigator.appVersion.match(/MSIE ([\d.]+);/)[1] >= 5.5) p = 'filter';

    return (getOpacityProperty = new Function("return '" + p + "';"))();
}

function fadeOpacity(sElemId, sRuleName, bBackward) {
    var elem = document.getElementById(sElemId);
    if (!elem || !getOpacityProperty() || !fadeOpacity.aRules[sRuleName]) return;

    var rule = fadeOpacity.aRules[sRuleName];
    var nOpacity = rule.nStartOpacity;

    if (fadeOpacity.aProc[sElemId]) { clearInterval(fadeOpacity.aProc[sElemId].tId); nOpacity = fadeOpacity.aProc[sElemId].nOpacity; }
    if ((nOpacity == rule.nStartOpacity && bBackward) || (nOpacity == rule.nFinishOpacity && !bBackward)) return;

    fadeOpacity.aProc[sElemId] = { 'nOpacity': nOpacity, 'tId': setInterval('fadeOpacity.run("' + sElemId + '")', fadeOpacity.aRules[sRuleName].nDalay), 'sRuleName': sRuleName, 'bBackward': Boolean(bBackward) };
}

fadeOpacity.addRule = function(sRuleName, nStartOpacity, nFinishOpacity, nDalay) { fadeOpacity.aRules[sRuleName] = { 'nStartOpacity': nStartOpacity, 'nFinishOpacity': nFinishOpacity, 'nDalay': (nDalay || 30), 'nDSign': (nFinishOpacity - nStartOpacity > 0 ? 1 : -1) }; };

fadeOpacity.back = function(sElemId) { fadeOpacity(sElemId, fadeOpacity.aProc[sElemId].sRuleName, true); };

fadeOpacity.run = function(sElemId) {
    var proc = fadeOpacity.aProc[sElemId];
    var rule = fadeOpacity.aRules[proc.sRuleName];

    proc.nOpacity = Math.round((proc.nOpacity + .1 * rule.nDSign * (proc.bBackward ? -1 : 1)) * 10) / 10;
    setElementOpacity(document.getElementById(sElemId), proc.nOpacity);

    if (proc.nOpacity == rule.nStartOpacity || proc.nOpacity == rule.nFinishOpacity) clearInterval(fadeOpacity.aProc[sElemId].tId);
}
fadeOpacity.aProc = {};
fadeOpacity.aRules = {};