if (document.cookie.indexOf("readerVersion") == -1) {
    var acrobat = new Object();
    acrobat.installed = false;
    if (!window.ActiveXObject) {
        if (navigator.plugins && navigator.plugins.length) {
            for (var x = 0; x < navigator.plugins.length; x++) {
                if (navigator.plugins[x].name.indexOf('Adobe Acrobat') != -1) {
                    acrobat.installed = true;
                    break;
                }
            }
        }
    } else {
        try {
            acrobat.control = new ActiveXObject('PDF.PdfCtrl');
        }
        catch (e) { }
        try {
            acrobat.control = new ActiveXObject('AcroPDF.PDF');
        }
        catch (e) { }
        if (acrobat.control) {
            acrobat.installed = true;
            acrobat.version = acrobat.control.GetVersions().split(',');
            acrobat.version = acrobat.version[0].split('=');
            acrobat.version = parseFloat(acrobat.version[1]);
        }
        acrobat.control = null;
    }
    document.cookie = "readerInstalled=" + (acrobat.installed ? 1 : 0);
    document.cookie = "readerVersion=" + (acrobat.version ? acrobat.version : -1);
}