Warning: explode() expects parameter 2 to be string, object given in E:\wamp\www\arihant\view_details.php on line 27 getting this error

Warning: explode() expects parameter 2 to be string, object given in
E:\wamp\www\arihant\view_details.php on line 27 getting this error

<?php
if(isset($_GET['b_no']))
{ $bno=$_GET['b_no'];
include("connect.php");
$query19="select * from billing where `b_no`=$bno";
$rs19=$conn->execute($query19);
if($rs19)
{
$itm=explode(',',$rs19['item']);
$qty=explode(',',$rs19['qty']);
$r=count($itm);
for($i=0;$i<=$r;$i++)
{
if(isset($itm[$i]) && isset($qty[$i]))
{
echo "item".$itm[$i];
echo "qty".$qty[$i];
echo "<br>";
}
}
}
else
{ echo "no records found";
}
}
else
{ echo "enter bill no";
}
?>
i am getting this warning every time when entering the b_no which is not
in the database . i am using ms access2007 as backend Warning: explode()
expects parameter 2 to be string, object given in on line 27