I used this code to add the data in the mysql table. But I do not know how to separate them because they are only stored in one column:

$birthday = mysql_real_escape_string($_POST['yyyy'] . '-' . $_POST['mm'] . '-' . $_POST['dd']); 

How do I load them in here, so that the month, day, and year will be separated:

<tr>
<td><font size="2">Birthday</td>
<td>
 <select title="- Select Month -" name="mm" id="mm" class="" > 
                              <option value=""  >--Month--</option> 
                              <option value="1" >Jan</option> 
                              <option value="2"  >Feb</option> 
                              <option value="3"  >Mar</option> 
                              <option value="4"  >Apr</option> 
                              <option value="5"  >May</option> 
                              <option value="6"  >Jun</option> 
                              <option value="7"  >Jul</option> 
                              <option value="8"  >Aug</option> 
                              <option value="9"  >Sep</option> 
                              <option value="10"  >Oct</option> 
                              <option value="11"  >Nov</option> 
                              <option value="12"  >Dec</option> 
                              </select> 
                      <input title="Day" type="text" onkeypress="return isNumberKey(event)" name="dd" value="" size="1" maxlength="2" id='numbers'/ > 
                      <input title="Year" type="text" onkeypress="return isNumberKey(event)" name="yyyy"  value="" size="1"  maxlength="4" id='numbers'/> </td>
    </tr>

Please help.