// the date format prototype
Date.prototype.format = function(f)
{
    if (!this.valueOf())
        return '';

    var gsMonthNames = new Array('January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December');
    var gsDayNames = new Array('Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday');
    var d = this;

    return f.replace(/(yyyy|mmmm|mmm|mm|dddd|ddd|dd|hh|nn|ss|a\/p)/gi,
        function($1)
        {
            switch ($1.toLowerCase())
            {
            case 'yyyy': return d.getFullYear();
            case 'mmmm': return gsMonthNames[d.getMonth()];
            case 'mmm':  return gsMonthNames[d.getMonth()].substr(0, 3);
            case 'mm':   return (d.getMonth() + 1).zf(2);
            case 'dddd': return gsDayNames[d.getDay()];
            case 'ddd':  return gsDayNames[d.getDay()].substr(0, 3);
            case 'dd':   return d.getDate().length == 1 ? '0' + d.getDate() : d.getDate();
            case 'hh':   return ((h = d.getHours() % 12) ? h : 12).zf(2);
            case 'nn':   return d.getMinutes().zf(2);
            case 'ss':   return d.getSeconds().zf(2);
            case 'a/p':  return d.getHours() < 12 ? 'a' : 'p';
            }
        }
    );
}