моя проблема заключается в том, когда я выбираю ежемесячную часть, следующее выпадающее меню не выходит. первая выпадающая работа хорошо работает, но когда я выбираю первый выбор, он ничего не отображает. это мой код
<td><h4 class="text-login">By Category           </h4></td> <td> <select name="selection"> <option value="">--Select--</option> <option value="1" id="month" type="select" >Monthly</option> <option value="2" id="year" type="select" >Yearly</option> </select> </td> <?php if(isset($_POST['Submit'])) { if(isset($_POST['selection']) && $_POST['selection'] == '1') { echo '<td><h4 class="text-login">Please select month           </h4></td>'; echo '<td>'; echo '<select name="month">'; echo '<option value="">--Select--</option>'; echo '<option value= "January" name = "first" id="month1" type="select" >January</option>'; echo '<option value="b2" id="month2" type="select" >February</option>'; echo '<option value="b3" id="month3" type="select" >March</option>'; echo '<option value="b4" id="month4" type="select" >April</option>'; echo '<option value="b5" id="month5" type="select" >May</option>'; echo '<option value="b6" id="month6" type="select" >June</option>'; echo '<option value="b7" id="month7" type="select" >July</option>'; echo '<option value="b8" id="month8" type="select" >August</option>'; echo '<option value="b9" id="month9" type="select" >September</option>'; echo '<option value="b10" id="month10" type="select" >October</option>'; echo '<option value="b11" id="month11" type="select" >November</option>'; echo '<option value="b12" id="month12" type="select" >December</option>'; echo '</select>'; echo '<tr>'; echo '<td><h4 class="text-login">Lab           </h4></td>'; echo '<td>'; $sql = "SELECT location FROM item "; $result = mysqli_query($conn,$sql); $rownum = mysqli_num_rows($result); echo '<select name="lab" >'; echo '<option value="">--Select--</option>'; $i=0; while ($row = mysqli_fetch_assoc($result)) { echo '<option value="" id="lab1" type="select"><?php echo $row["location"];?></option>'; $i++; } echo '</select>'; echo '</td><tr><td align="right">'; echo '</table></center>'; } else { echo '<td><h4 class="text-login">Please select month/year           </h4></td>'; echo '<td>'; echo '<select name="" onchange = "">'; echo '<option value="">--Select--</option>'; echo '<option value="t8" id="year8" type="select" >2000</option>'; echo '<option value="t9" id="year9" type="select" >2001</option>'; echo '<option value="t10" id="year10" type="select" >2002</option>'; echo '<option value="t11" id="year11" type="select" >2003</option>'; echo '<option value="t12" id="year12" type="select" >2004</option>'; echo '<option value="t12" id="year12" type="select" >2005</option>'; echo '<option value="t12" id="year12" type="select" >2006</option>'; echo '<option value="t12" id="year12" type="select" >2007</option>'; echo '<option value="t12" id="year12" type="select" >2008</option>'; echo '<option value="t12" id="year12" type="select" >2009</option>'; echo '<option value="t12" id="year12" type="select" >2010</option>'; echo '<option value="t12" id="year12" type="select" >2011</option>'; echo '<option value="t12" id="year12" type="select" >2012</option>'; echo '<option value="t12" id="year12" type="select" >2013</option>'; echo '<option value="t12" id="year12" type="select" >2014</option>'; echo '<option value="t12" id="year12" type="select" >2015</option>'; echo '</select>'; echo '</td><tr><td align="right">'; } } ?> </tr> </table></center>