คำสั่ง insert ผิดตรงไหนออ่ะ งง

$dateorder =  date("$e_date");

$dateime1 = $dateorder;
$date = explode('/', $dateime1);
$newdate = implode('-', array($date[2], $date[1], $date[0]));	

		for ($n=0;$n<count($sess_idproduct);$n++) {
		$sql1= "insert into tb_order("pId,refid,pNum,pPrice,date,id_cus"," '$sess_idproduct[$n]','$randnum','$sess_num[$n]','$sess_price[$n]','$newdate','$usermem'  ","tb_order")";
		mysql_db_query($db,$sql1);
		echo $sql1;
$sql_data = "update products set  amount = amount-$sess_num[$n] where productscode = '$sess_idproduct[$n]'";
mysql_query($sql_data);