How to Select Numbers from Combobox with php?

I have a Combobox (<select><option></option></select>) and It consists of 31 numbers, the following code :

<select name='Bday' id='Bday' >
  <option value="1">1</option>
  <option value="2">2</option>
  <option value="3">3</option>
  <option value="4">4</option>
  <option value="5">5</option>
  <option value="6">6</option>
  <option value="7">7</option>
  <option value="8">8</option>
  <option value="9">9</option>
  <option value="10">10</option>
  <option value="11">11</option>
  <option value="12">12</option>
  <option value="13">13</option>
  <option value="14">14</option>
  <option value="15">15</option>
  <option value="16">16</option>
  <option value="17">17</option>
  <option value="18">18</option>
  <option value="19">19</option>
  <option value="20">20</option>
  <option value="21">21</option>
  <option value="22">22</option>
  <option value="23">23</option>
  <option value="24">24</option>
  <option value="25">25</option>
  <option value="26">26</option>
  <option value="27">27</option>
  <option value="28">28</option>
  <option value="29">29</option>
  <option value="30">30</option>
  <option value="31">31</option>
</select>

I want the page number is 25 received, Combobox to view it. for example , if the address of page http//test.php?page=25,combobox view 25... No change in the combobox code!

Solution

Create your select options in a loop, and in each iteration check if the current value equals the one you get from the page get variable.

For brevity i have used the ternary operator in this example:

<?php $pageno = isset($_GET['page'])?$_GET['page']:''; ?>

<select name='Bday' id='Bday' >

<?php for($i=1;$i<=31;$i++):?>

    <option value="<?php echo $i;?>" <?php echo $i==$pageno? 'selected':'';?> ><?php echo $i;?></option>

<?php endfor;?>

</select>