js日期操作

 function CreateDate()
            {
                if(!req('txtInputDate','输入日期')){return;}
             if(!matchDate('txtInputDate')){return;}
           
                var strDate = $('txtInputDate').value;
               
                var tmp1 =new Date(Date.parse(strDate.replace(/-/g,"//")));               
               
                var tmp2 =new Date(tmp1.getFullYear()+parseInt(3),tmp1.getMonth(),tmp1.getDate()-1);
               
                var strYear     =tmp2.getFullYear()
                var strMonth    =tmp2.getMonth()+1;
                var strDate     =tmp2.getDate();               
               
                var strDate     =strYear+"-"+((strMonth<10)?("0"+strMonth):(strMonth))+"-"+((strDate<10)?("0"+strDate):(strDate));
               
                $('txtValidDate').value = strDate;
            }