php mysql ช่วยหน่อยค่ะ ทำไมดึงข้อมูลมาแสดงที่ list box / list menuไม่ได้

echo "<td bgcolor=#FFCC00><font face=Ms Sans Serif><b>Road : </b></font></td>";
echo "<td bgcolor=#FFCC00 colspan=2><select name=road_id>";
$Result = pg_query($dbconn,"Select * From tbroad");
while($cate=pg_fetch_array($Result)){
if($rs["road_id"]==$cate["road_id"]){
echo"<option value=".$cate["road_id"]."selected>".$cate["road_name"]."</option>";}
else{
echo"<option value=".$cate["road_id"].">".$cate["road_name"]."</option>";}
}
?>
</select>
<?
echo "</td>";
echo "</tr>";