获取上个月的起止时间

	$(function(){
	// 日期初始化
	 alert(getStartDate());
	 alert(getEndDate());
	
});

//获取开始时间
function getStartDate(){
	var date = new Date();
	var year = date.getFullYear();
	var m = date.getMonth();
	var month = "";
	if (m == 0) {
		year -= 1;
		month = "12";
	} else if(0 < m && m < 9){
		month = "0" + m;
	} else {
		month = "" + m;
	}
	return year + month + "01";
}

//获取结束时间
function getEndDate(){
	var date = new Date();
	var year = date.getFullYear();
	var m = date.getMonth();
	var month = "";
	if (m == 0) {
		year -= 1;
		month = "12";
	} else if(0 < m && m < 9){
		month = "0" + m;
	} else {
		month = "" + m;
	}
	var day = new Date(date.getFullYear(),month,0).getDate();
		
	return year + month + day;
}