// extend date prototype.
        Date.prototype.monthNames = [
            "January", "February", "March",
            "April", "May", "June",
            "July", "August", "September",
            "October", "November", "December"
        ];

        Date.prototype.getMonthName = function() {
            return this.monthNames[this.getMonth()];
        };
        Date.prototype.getShortMonthName = function () {
            return this.getMonthName().substr(0, 3);
        };

// usage:

//var d = new Date();
//alert(d.getMonthName());      // "October"
//alert(d.getShortMonthName()); // "Oct"