function nowtime(){//將當前時間轉換成yyyymmdd格式    var mydate = new Date();    var str = "" + mydate.getFullYear();    var mm = mydate.getMonth()+1    if(mydate.getMonth()>9){     str += mm;    }    else{     str += "0" + mm;    }    if(mydate.getDate()>9){     str += mydate.getDate();    }    else{     str += "0" + mydate.getDate();    }    return str;  }