function retrieveCookie( cookieName ) {
        /* retrieved in the format
        cookieName4=value; cookieName3=value; cookieName2=value; cookieName1=value
        only cookies for this domain and path will be retrieved */
        var cookieJar = document.cookie.split( "; " );
        for( var x = 0; x < cookieJar.length; x++ ) {
                var oneCookie = cookieJar[x].split( "=" );
                if( oneCookie[0] == escape( cookieName ) ) { return unescape( oneCookie[1] ); }
        }
        return null;
}

function setCookie( cookieName, cookieValue, lifeTime, path, domain, isSecure ) {
        if( !cookieName ) { return false; }
        if( lifeTime == "delete" ) { lifeTime = -10; } //this is in the past. Expires immediately.
        /* This next line sets the cookie but does not overwrite other cookies.
        syntax: cookieName=cookieValue[;expires=dataAsString[;path=pathAsString[;domain=domainAsString[;secure]]]]
        Because of the way that document.cookie behaves, writing this here is equivalent to writing
        document.cookie = whatIAmWritingNow + "; " + document.cookie; */
        document.cookie = escape( cookieName ) + "=" + escape( cookieValue ) +
                ( lifeTime ? ";expires=" + ( new Date( ( new Date() ).getTime() + ( 1000 * lifeTime ) ) ).toGMTString() : "" ) +
                ( path ? ";path=" + path : "") + ( domain ? ";domain=" + domain : "") +
                ( isSecure ? ";secure" : "");
        //check if the cookie has been set/deleted as required
        if( lifeTime < 0 ) { if( typeof( retrieveCookie( cookieName ) ) == "string" ) { return false; } return true; }
        if( typeof( retrieveCookie( cookieName ) ) == "string" ) { return true; } return false;
}