<select name="select2" id="label">
<?php  
   $imgdir = '/firma/foto';
  $dimg = opendir($imgdir);  
   while($imgfile = readdir($dimg))  
   {  
     $a_img[] = $imgfile;  
     sort($a_img);  
     reset ($a_img);  
   }  
   $totimg = count($a_img);
   for($x=0; $x < $totimg; $x++)  
   {  
     echo "<option value=".$a_img[$x].">" . $a_img[$x]."</option>";
   }  
   ?>
</select>