document.write('<option value=-1>--</option>')
document.write('<option value=1>01</option>')
document.write('<option value=2>02</option>')
document.write('<option value=3>03</option>')
document.write('<option value=4>04</option>')
document.write('<option value=5>05</option>')
document.write('<option value=6>06</option>')
document.write('<option value=7>07</option>')
document.write('<option value=8>08</option>')
document.write('<option value=9>09</option>')
document.write('<option value=10>10</option>')
document.write('<option value=11>11</option>')
document.write('<option value=12>12</option>')
document.write('<option value=13>13</option>')
document.write('<option value=14>14</option>')
document.write('<option value=15>15</option>')
document.write('<option value=16>16</option>')
document.write('<option value=17>17</option>')
document.write('<option value=18>18</option>')
document.write('<option value=19>19</option>')
document.write('<option value=20>20</option>')
document.write('<option value=21>21</option>')
document.write('<option value=22>22</option>')
document.write('<option value=23>23</option>')
document.write('<option value=24>24</option>')
document.write('<option value=25>25</option>')
document.write('<option value=26>26</option>')
document.write('<option value=27>27</option>')
document.write('<option value=28>28</option>')
document.write('<option value=29>29</option>')
document.write('<option value=30>30</option>')
document.write('<option value=31>31</option>')