<option <?php if ($mois_debut_periode == "01") echo "selected"; ?> >01</option>
<option <?php if ($mois_debut_periode == "02") echo "selected"; ?> >02</option>
<option <?php if ($mois_debut_periode == "03") echo "selected"; ?> >03</option>
<option <?php if ($mois_debut_periode == "04") echo "selected"; ?> >04</option>
<option <?php if ($mois_debut_periode == "05") echo "selected"; ?> >05</option>
<option <?php if ($mois_debut_periode == "06") echo "selected"; ?> >06</option>
<option <?php if ($mois_debut_periode == "07") echo "selected"; ?> >07</option>
<option <?php if ($mois_debut_periode == "08") echo "selected"; ?> >08</option>
<option <?php if ($mois_debut_periode == "09") echo "selected"; ?> >09</option>
<option <?php if ($mois_debut_periode == "10") echo "selected"; ?> >10</option>
<option <?php if ($mois_debut_periode == "11") echo "selected"; ?> >11</option>
<option <?php if ($mois_debut_periode == "12") echo "selected"; ?> >12</option>
