var expd = 30;
var exp = new Date();
exp.setTime(exp.getTime() + (expd * 24 * 60 * 60 * 1000));

function getCookieVal(offset){
    var endstr = document.cookie.indexOf(";", offset);
    if (endstr == -1) 
        endstr = document.cookie.length;
    return unescape(document.cookie.substring(offset, endstr));
}

function GetCookie(name){
    var arg = name + "=";
    var alen = arg.length;
    var clen = document.cookie.length;
    var i = 0;
    while (i < clen) {
        var j = i + alen;
        if (document.cookie.substring(i, j) == arg) 
            return getCookieVal(j);
        i = document.cookie.indexOf(" ", i) + 1;
        if (i == 0) 
            break;
    }
    return null;
}

function SetCookie(name, value){
    var argv = SetCookie.arguments;
    var argc = SetCookie.arguments.length;
    var expires = (argc > 2) ? argv[2] : null;
    var path = (argc > 3) ? argv[3] : null;
    var domain = (argc > 4) ? argv[4] : null;
    var secure = (argc > 5) ? argv[5] : false;
    document.cookie = name + "=" + escape(value) +
    ((expires == null) ? "" : ("; expires=" + expires.toGMTString())) +
    ((path == null) ? "" : ("; path=" + path)) +
    ((domain == null) ? "" : ("; domain=" + domain)) +
    ((secure == true) ? "; secure" : "");
}

function DeleteCookie(name){
    document.write('a');
    var exp = new Date();
    exp.setTime(exp.getTime() - 1);
    var cval = GetCookie(name);
    document.cookie = name + "=" + cval + "; expires=" + exp.toGMTString();
}

function BackCol(color){
    document.body.style.backgroundColor = color;
    SetCookie('bcolor', color, exp);
}

function DefColor(color){
    var tmpcolor = GetCookie('bcolor');
    if (tmpcolor == null) {
        tmpcolor = color;
    }
    BackCol(tmpcolor);
}