function set_cookie (name, value,expires) {
	var argv = set_cookie.arguments;
	var argc = set_cookie.arguments.length;
	var path = (argc > 3) ? argv[3] : null;
	var domain = (argc > 4) ? argv[4] : null;
	/*
	var expires = new Date();
	var today = new Date();
	var msPerMonth = 24*60*60*1000*31;
	expires.setTime( today.getTime() + msPerMonth );
	*/

	st = sName + "=" + encodeURI(sValue) + ((expires == null) ? "" : ("; expires=" + expires))
			+ ((path == null) ? "" : ("; path=" + path))
			+ ((domain == null) ? "" : ("; domain=" + domain));
	document.cookie = st;
}

function get_cookie(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) {
                        offset=j;
                        var endstr = document.cookie.indexOf (";", offset);
                        if (endstr == -1)
                                endstr = document.cookie.length;
                        return decodeURI(document.cookie.substring(offset, endstr));
                }
                i = document.cookie.indexOf(" ", i) + 1;
                if (i == 0)
                        break;
        }
        return null;
}

function del_cookie(name) {
        var expdate = new Date ();
        expdate.setTime (expdate.getTime()-1);
        set_cookie (name, "", expdate)
}