var date = new Date(); //日期对象
    var now = "";
     now = date.getFullYear()+"-"; 
     now = now + (date.getMonth()+1)+"-";
     now = now + date.getDate();
     alert(now);

    //日期增加函数
    function  dateAdd(s,dtDate) {
        var  dtTmp  =  new  Date(dtDate);
        if  (isNaN(dtTmp))  dtTmp  =  new  Date();
        var m=dtTmp.getMonth();
        if(s=="w"){
            dtTmp=new  Date(Date.parse(dtTmp)  +  86400000  *  7);
        }else{
            dtTmp=new  Date(dtTmp.getFullYear(),dtTmp.getMonth() + 1,  dtTmp.getDate());
            if(dtTmp.getMonth()>m+1){
                dtTmp=new  Date(dtTmp.getFullYear(),dtTmp.getMonth(), 0);
            }
        }
        return dtTmp.getFullYear()+"-"+(dtTmp.getMonth() +1)+"-"+dtTmp.getDate()
    }
    alert(dateAdd("w",new Date(2012,10-1,29))); //得出 2012-11-5
    alert(dateAdd("m",new Date(2012,10-1,31))); //得出 2012-11-30
    //注意传入的月份比实现小1【0-11】