HOW TO USE IF COMMAND WITH COMBO BOX TO SELECT AN OPTION

I have been having challenges with using combobox and if statement to select an option. pls kindly help me. I want to select an option if a combobox is selected. this is the code below. Any help will be highly appreciated. Thanks

<tr><td>TERM</td>
                    <td>&nbsp;</td>
                    <td><select name="term"  title="term" required>
                    <option ></option>
                    <option value="FIRST">FIRST TERM </option>
                    <option value="SECOND">SECOND TERM </option>
                    <option value="THIRD">THIRD TERM </option>

                  </select></td></tr>

                <td> subjectcode</td>
                <td>&nbsp;</td>
                <td><select name="code" required >
                    <option></option>
                    <?php
                    if option.value.select='FIRST' 
                  $result = mysql_query("SELECT * FROM subject where arm='JSS' AND TERM='FIRST' ");
                    $result = mysql_query("SELECT * FROM subject where arm='JSS' AND TERM='FIRST' ");


                                echo '<option value="'.$row['CODE'].'">';
                                echo $row['CODE'];
                                echo '</option>';
                            }


                        ?>
                        <?php
                        else if option.value.select='SECOND' 
                  $result = mysql_query("SELECT * FROM subject where arm='JSS' AND TERM='SECOND' ");


                            {  
                                echo '<option value="'.$row['CODE'].'">';
                                echo $row['CODE'];
                                echo '</option>';
                            }


                        ?>
                        <?php
                        else if option.value.select='THIRD' 
                  $result = mysql_query("SELECT * FROM subject where arm='JSS' AND TERM='THIRD' ");

                        //$result = mysql_query("SELECT * FROM subject ");
                        while($row = mysql_fetch_array($result))
                            {  
                                echo '<option value="'.$row['CODE'].'">';
                                echo $row['CODE'];
                                echo '</option>';
                            }


                        ?>


                  </select>