js parser date

Date.prototype.format = function(format) {
	var o = {
		"M+" : this.getMonth()+1,
		"d+" : this.getDate(),
		"h+" : this.getHours(),
		"m+" : this.getMinutes(),
		"s+" : this.getSeconds(),
		"q+" : Math.floor((this.getMonth()+3)/3),
		"S"  : this.getMilliseconds()
	};
	if(/(y+)/.test(format)) format = format.replace(RegExp.$1,(this.getFullYear()+"").substr(4 - RegExp.$1.length));
	for(var k in o)
		if(new RegExp("("+ k +")").test(format)) format = format.replace(RegExp.$1,RegExp.$1.length==1 ? o[k] :("00"+ o[k]).substr((""+ o[k]).length));
	return format;
};


var date1 = '01/12/2012';
var date2 = '2012/1/13';
var date3 = 'Jan 14, 2012';
var date4 = 'January 15, 2012';

var date = new Date(date4);
alert(date.format('yyyy-MM-dd'));