Error related to updating quantity in table

Error related to updating quantity in table

Hi Experts,
I need your help to resolve this issue in my script as I am trying to
update a quantity of the product in products table based on getting
information via post from the first page. everything seems ok but the
quantity is not getting updated in the table. table already had some
quantity for this product.
Page 1:
$selectP="select prodid, prodname, prodtype from products where prodtype
= 'BP'";
$result=mysql_query($selectP) or die (mysql_error());
echo "<form method=POST action=quantupdate.php>";
echo "<center><table border=1 cellpadding=5>";
echo "<tr><td>Select a Product to Update Quantity in Stock </td>";
echo "<td>";
echo "<select size=\"1\" name=\"product_selection\"
id=\"product_selection\">";
echo "<option value=\"0\">- Product -</options>";
while($row = mysql_fetch_array($result)) {
echo "<option value='".$row['prodid']."'>".$row['prodname']."</option>";
}
echo "</select>";
echo "<tr><td>Select Quantity </td>";
echo "<td>";
echo "<select size=\"1\" name=\"pq\" id=\"pq\">";
echo "<option value=\"0\">Select Qty</options>";
echo "<option value=\"5\">5</options>";
echo "<option value=\"10\">10</options>";
echo "<option value=\"20\">20</options>";
echo "<option value=\"30\">30</options>";
echo "</select>";
echo "<tr><td><input type=submit name=submit id=submit value='Update
Now'></td>";
echo "<td><input type=reset value='Clear Form'></td></tr>";
echo "</table></center>";
echo "</form>" ;
Page 2:
$bprod=$_POST['product_selection'];
$quantity=$_POST['pq'];
if(isset($_REQUEST['product_selection'])) {
$bprod=$_POST['product_selection'];
} else {
echo "Not Working???";//do something about it
}
$updatequantity="UPDATE products
SET prodquantity = ".$quantity." WHERE prodname = ".$bprod;
$exeupdatequantity=mysql_query($updatequantity);
everything seems ok, no error message but table is not getting updated
with the new quantity.
Pls help. Many thanks in advance.