Thanks I did it as follows:
echo "<select name=\"month\">";
$mnts=array(0,Jan,Feb,Mar,Apr,May,Jun,Jul,Aug,Sep,Oct,Nov,Dec);
for ($i=1; $i<13; $i++)
{
if($_POST['month']==$i){$sel="selected";}else{$sel=null;}
echo "<option value=$i $sel>$mnts[$i]</option>";
}
echo "</select>";