[RESOLVED] whats wrong with my code

[saraa]

Hi all..may i know what is wrong with my codes..
I have 2 tables..company(com_id,com_code,com_name) and purchase(po_id,po_no,com_code).Now i want to insert all values.
There are one drop down combo in my form to display com_name.Now I want to insert value of com_code.Can someone let me know why com_code not saved into my db.

Here is my codes:
In form

<td><select name="com_name"> 
            <? 
                $sqlst = mysql_query("SELECT com_name,com_code FROM company  ORDER BY com_name"); 
                while($company = mysql_fetch_array($sqlst)){ ?> 
                <option value="<? echo $company['com_code'] ?>"><? echo $company['com_name'] ?> 
                </option> 
                <? } ?> 
              </select></td>

In Insert Process

<? 
include ("../../odbc.php"); 

echo $po_no=$_POST['po_no']; 
echo $po_date=$_POST['po_date']; 
echo $com_name=$_POST['com_name']; 
echo $com_code=$_POST['com_code'];

$query_add_data = "INSERT INTO purchase(po_no,po_date,com_code) VALUES ('$po_no','$po_date','$com_code')";
$result=mysql_query($query_add_data) or die("Could Not Add");

echo "<META HTTP-EQUIV=Refresh CONTENT=\"5; URL=add_stockin.php\">";

?>

Thanks in advance